I was practicing for my English test then I came across this question.     This is one of the best novels that have appeared this year.         that   that has   to have   No improvement      According to me the answer to this question should be "that has" in place of "that have" but the answer is No improvement.  So I am a little confused that why is it not ("that has") the right answer because we are talking about one singular book out of so many.  I get confused a lot of times at such questions.
In the sentence      It's one of the best films that has/have ever been made   What should the verb agreement be?
Why can't the Klein-Gordon equation with a Couloumb potential describe the hydrogen atom?  Why can the first order Dirac equation explain it? What are the failures? How do I share variables between two functions? So...here is part of my code for a plugin.  I'm a newb of sorts so be kind.  I've read up on global variables but I can't seem to get it to work and I've read you shouldn't use them anyway.  So what would be the best way to write the code below without having to re-declare the variables for each function?  Here is the  if necessary.  // Display the product badge on the shop page  add_action( 'woocommerce_after_shop_loop_item_title', 'wc_simple_product_badge_display_shop', 30 ); function wc_simple_product_badge_display_shop() {     $title = get_post_meta( get_the_ID(), '_wc_simple_product_badge_title', true ); // badge title     $class = get_post_meta( get_the_ID(), '_wc_simple_product_badge_class', true ); // badge class     $duration = get_post_meta( get_the_ID(), '_wc_simple_product_badge_duration', true ); // badge duration     $postdate = get_the_time( 'Y-m-d' ); // post date     $postdatestamp = strtotime( $postdate ); // post date in unix timestamp     $difference = round ((time() - $postdatestamp) / (24*60*60));  // difference in days between now and product's post date      if ( !empty( $title ) &amp;&amp; empty( $duration ) || !empty( $title ) &amp;&amp; $difference &lt;= $duration ){ // Check to see if there is a title and the product is still within the duration timeframe if specified         $class = !empty( $class ) ? $class : '';         echo '&lt;span class="wc_simple_product_badge ' . $class . '"&gt;' . $title . '&lt;/span&gt;';     } }  // Display the product badge on the single page  add_filter( 'woocommerce_single_product_image_html', 'wc_simple_product_badge_display_single' );     function wc_simple_product_badge_display_single( $img_html ) {     $title = get_post_meta( get_the_ID(), '_wc_simple_product_badge_title', true ); // badge title     $class = get_post_meta( get_the_ID(), '_wc_simple_product_badge_class', true ); // badge class     $duration = get_post_meta( get_the_ID(), '_wc_simple_product_badge_duration', true ); // badge duration     $single_opt = get_post_meta( get_the_ID(), '_wc_simple_product_badge_single_page_option', true ); // badge on single page     $postdate = get_the_time( 'Y-m-d' ); // post date     $postdatestamp = strtotime( $postdate ); // post date in unix timestamp     $difference = round ((time() - $postdatestamp) / (24*60*60));  // difference in days between now and product's post date      if ( !empty( $title ) &amp;&amp; empty( $duration ) &amp;&amp; $single_opt === 'yes' || !empty( $title ) &amp;&amp; $difference &lt;= $duration &amp;&amp; $single_opt === 'yes' ){ // Check to see if there is a title and the product is still within the duration timeframe ()if specified) and the checkbox is checked to show on single page view         $class = !empty( $class ) ? $class : '';         echo '&lt;span class="wc_simple_product_badge ' . $class . '"&gt;' . $title . '&lt;/span&gt;';         return $img_html; }      elseif ( $single_opt === 'no' ) { // Check to see if the checkbox is unchecked to show on single page view         return $img_html;     }  } How can one change the timestamp of an old commit in Git? The answers to  describe a way to amend previous commit messages that haven't yet been pushed upstream.  The new messages inherit the timestamps of the original commits.  This seems logical, but is there a way to also re-set the times? I am trying to define a proof for  $A \cup B = B$ if and only if $A \subset B$  I started with:  $$A \cup B$$ $$x \in A \lor x \in B$$   but I am unsure on how to continue. Why did Obi-Wan allow Leia to get adopted by such a high profile figure? Show that $ \sum_{n=2}^m \binom{n}{2} = \binom{m+1}{3}$ I need a hand in showing that $$ \sum_{n=2}^m \binom{n}{2} = \binom{m+1}{3}$$   Thanks in advance for any help. How do you transpose tensors? We transpose a matrix $A$ by replacing $A_{ij}$ with $A_{ji}$, for all $i$ and $j$.  However, in case $A$ has more than two dimensions (that is, it is a tensor), I don't know how to apply the transpose operation.   If A has dimensions $3\times 3 \times 8$, then what will replace $A_{ijk}$?  If $A$ has shape $3\times 3\times 8\times 8$, then what will replace $A_{ijkl}$? What happened to Jarvis at the end of Avengers: Age of Ultron How can I work around this TikZ bug: (\x)^2 and \x^2 produce different results in TikZ plot? I have some files with TikZ graphics that have suddenly changed appearance since I upgraded to PGF-2.10.  Here is a minimal example:  \documentclass{minimal} \usepackage{tikz} \begin{document} \pgfversion\par \begin{tikzpicture} \draw[blue] plot[domain=-1:1] (\x,{\x^2 + \x^3}); \draw[xshift=4cm,blue] plot[domain=-1:1] (\x,{(\x)^2 + (\x)^3}); \end{tikzpicture} \end{document}   In PGF 2.00 I had this:    while in 2.10 I have this:    The one on the left in PGF 2.10 looks like the graph of y=x^3 but could also be y=x^3 + x|x|.   This has been  on sourceforge and  on the pgf-users mailing list.  Although I haven't checked myself yet, the bug remains open and some of the commenters below report that problems still exist in the CVS version.   Geoffrey Jones notes the bug is in the 2.00 CVS version:     Hi Matthew, not an answer, just an FYI   that's too large for the comment box.   My compile of your code through pgf   v2.00 produces the result you see with   v2.10, above:       I.e., the difference you observe seems   to pre-date v2.10.   There is a workaround by inserting parentheses.  But since I have so many old lecture files I'd rather find a solution that doesn't involve rewriting my TikZ code.  And I'm squeamish about using the CVS bleeding edge code even if it were fixed, since I don't want to introduce other problems.  Ideally I'd like a simple patch that I can stick at the preamble, or just fix one file in the PGF distro. I've seen plots of test/training error suddenly dropping at certain epoch(s) a few times during the neural network training, and I wonder what causes these performance jumps:    This image is taken from Kaiming He's Github, but similar plots show up in many papers. Sorry if this is very basic but here's a question.   Let $\mathbf{v}=(v_1,\ldots, v_n)\in k^n$ where $k=\bar{k}$.      Why do we have   $$ \sqrt{\sum_{i=1}^n |v_i|^2} \leq \sum_{i=1}^n |v_i|,  $$   where the left-hand side can be thought of as the $2$-norm $\|\mathbf{v}\|_2$ on $L^2(k^n)$?   $\mathbf{General \; case}$: If this is true for $p=2$-norm, I am guessing that this is true for all $p\geq 1$:  $$ \left( \sum_{i=1}^n |v_i|^p\right)^{1/p}\leq \sum_{i=1}^n |v_i|.  $$     In fact, does this inequality hold when $p$ is a rational number? How to add appendix in thesis using LyX I want to add an appendix (questionnaire etc.) at the end of my thesis after the references. I use the article class and work with LyX: Document -&gt; Start appendix here. But I am not getting it in the TOC.  \documentclass[12pt,english]{article} \usepackage[T1]{fontenc} \usepackage[latin9]{inputenc} \setlength{\parskip}{\smallskipamount} \setlength{\parindent}{0pt} \usepackage{color} \definecolor{document_fontcolor}{rgb}{0, 0, 0} \color{document_fontcolor} \usepackage{babel} \usepackage{float} \usepackage{textcomp} \usepackage{pdfpages} \usepackage{tipa} \usepackage{amsmath} \usepackage{graphicx} \usepackage{setspace} \PassOptionsToPackage{normalem}{ulem} \usepackage{ulem} \usepackage[unicode=true,  bookmarks=true,bookmarksnumbered=false,bookmarksopen=false,  breaklinks=false,pdfborder={0 0 0},backref=false,colorlinks=false]  {hyperref}  \makeatletter  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% LyX specific LaTeX commands. %% Because html converters don't know tabularnewline \providecommand{\tabularnewline}{\\} %% A simple dot to overcome graphicx limitations \newcommand{\lyxdot}{.}   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands. \numberwithin{equation}{section}  \@ifundefined{date}{}{\date{}} \@ifundefined{showcaptionsetup}{}{%  \PassOptionsToPackage{caption=false}{subfig}} \usepackage{subfig} \makeatother  \appendix \noindent \begin{center} \textbf{Questionnaire (Case Study 1)} \par\end{center} Examples and Counterexamples of Relations which Satisfy Certain Properties Definition: Given a set $X$, a relation $R$ on $X$ is any subset of $X\times X$.  A relation $R$ on $X$ is said to be  reflexive if $(x,x) \in R$ for all $x \in X$, irreflexive if $(x,x) \not\in R$ for all $x \in X$, transitive if $(x,y) \in R$ and $(y,z) \in R$ implies that $(x,z)\in R$, intransitive (or antitransitive) if $(x,y) \in R$ and $(y,z) \in R$ implies that $(x,z)\not\in R$, symmetric if $(x,y) \in R$ implies that $(y,x) \in R$, antisymmetric if $(x,y) \in R$ and $(y,x) \in R$ implies that $x=y$.   Given any combination of the properties listed above, is there a nontrivial (i.e. nonempty) relation which satisfies that combination of properties? On Ubuntu 18.04, I have connected my laptop to an external display and I am able to set the external display as primary and external display only mode. But when I turn on my laptop or log out from my session the display login screen is displayed only on my(internal) laptop screen. But once I login the display switches to external only and my laptop screen turns off as expected. Is there a way I can make the login screen appear only on the external screen on bootup or on logout as in 16.04? Also the login screen does not follow my cursor as in 16.04. How do I disable a bottom panel with the list of open windows on GNOME 3? How do I disable "Workspace dock" (a bottom panel with the list of open windows and a workspace indicator-cum-switcher), the one that is over "Plank" in the screenshot below?    I'm using Ubuntu 17.10. How do I get the current date and time in PHP? Which PHP function can return the current date/time? How to configure Jaybird with hibernate Why can't ARIMA model large lags and/or long range dependence? ARIMA cannot model large lags (obtained from autocorrelation plot) and long range dependency (hurst exponent $H &gt; 0.5$). Why is it so? EDIT:  My question was poorly worded.   I wasn't asking about showing $\ln(1+x) &gt; \frac{2x}{2+x}$ for $x&gt;0$.   What I wanted to know is why the lower bound provided by $ \frac{2x}{2+x}$ was so tight for small positive values of $x$. This is addressed in robjohn's answer. combine 2 fields in 1 to use it in the "group by" section of the reports is it possible to combine two fields in one and use that field to group by in reports? for example, i would like to combine ee id and ee name fields in 1 and show as 1 field in the "group by" section on reports.