When can the relative pronoun be omitted? This is not very clear for me. I don't understand the rules.
"For someone used to the tiny creatures we get in England it was something of a shock."  I think, in this sentence, relative pronouns before some words have been omitted. I know rules of omitting relative pronouns, but in this case I have failed to understand before which words relative pronouns can be placed to understand the sentence perfectly, which has been stated above. Please, explain the rules of omitting relative pronouns with the help of the sentence stated above, so that I can be able to understand this type of sentences easily. You can also use other sentences to explain this fact clearly.  Thanks to everyone.
I have seen many softwares such as Update Manager and Synaptic Package Manager, they wait if some other program is using the /var/lib/dpkg/lock and is locked. How can we do this through the Terminal? I saw apt-get's manual but didn't find anything useful. Could someone please provide an explanation for the origin of ? (Ideally someone who I have been speaking with on the h-bar)  Any advanced maths beyond basic calculus will most probably leave me at a loss, though I do not mind a challenge! Please assume little prior knowledge, as over the past few days I have discovered that much of my understanding surrounding the process as virtual particle pairs is completely wrong. If derivative of function is less than or equal to 4, prove the existence of point $c$ so $f(c)=c^2$. I am struggling to construct a simple proof of the following.  Suppose $f(x)$ is differentiable for any real value $x$ and that $f'(x) \le 4$ for all real values of x. Prove there is at most one real value $c&gt;2$ such that $f(c) =c^2$.  I am completely lost on where to start on this proof and any help would be greatly appreciated! I want to know all sets of single-variate functions that fulfill the following qualities: $\forall_{f:R^2 \to R^2} \forall_{g \in CAF} \forall_{h \in CAF} \exists_{k\in CAF} k(x) = f(g(x),h(x))$ where CAF is the set I am wishing to find. I know that the set of constants and the set of piece wise constants each satisfy that equation. Do any others? Words for "a bit sad" and "a bit happy"? First axiom of sheaves: in noetherian topological spaces the direct limit presheaf is a sheaf. How can I watch Amazon Prime videos using Firefox on Ubuntu 16.04? How can I watch Amazon Prime videos using Firefox on Ubuntu 16.04? Currently Firefox version is 48.0. When I attempt to watch a video, I get the following Digital Rights Error message:  Your web browser is missing a digital rights component. In your web browser’s address bar, type about:addons, press Enter, and then on the left, click Plugins. For the Widevine Content Decryption Module, select Always Activate, and then refresh the video’s page and try watching the video. If the video doesn’t play, go back to Plugins, click the gear icon at the top of the page, and then click Check for Updates. When the plugins have updated, refresh the video’s page, and then try watching the video.  I didn't find Widevine Content Decryption Module. I searched for a solution, but it didn't work... One solution I found was to sudo apt-get install flashplugin-installer and then do the following: sudo apt-add-repository ppa:flexiondotorg/hal-flash sudo apt-get update &amp;&amp; sudo apt-get install libhal1-flash  However, it didn't work and I still got the same Digital Rights Error message. I am able to watch Amazon Prime videos using Google Chrome, but not with Firefox. I want to know if it's possible on Firefox on Ubuntu 16.04. Is it safe to disable System Integrity Protection? While using OS X El Capitan 10.11.x, is it safe to disable System Integrity Protection? There are all these additional apps that modify folders and the dock that I want to install but you have to disable rootless first.  Good idea or bad idea? Number of Pairs of Subsets Find the number of Pairs $(A,B)$ of subsets of $[n]$ such that $A ⊆ B$? I just need clarification in my thought process. My professor's wording at times can through me off. I just want to know if I am on the right track. We will have $3$ regions: 1.Outside $B$ 2.Inside $A$ 3. Inside $B$, Outside $A$ I believe the number of pairs is $3^n$ but I am not sure. Any help would be appreciated. If a ring element is right-invertible, but not left-invertible, then it has infinitely many right-inverses. Let $A$ be a ring and $a\in A$ an element that has a right-inverse but does not have a left-inverse. Show that $a$ has infinitely many right-inverses. I have a Canon XTI which I've been using for a few years now. Most of the time I'm been shooting in one of the "semi-manual" modes like aperture priority or shutter priority, but now I'd like to try using full manual mode. I should have a new EF-S 17-55 f/2.8 delivered when I get home today. Before I was using a variable aperture Sigma 17-70 which made manual mode more difficult with the aperture changing arbitrarily.  I understand the effect of changing aperture and shutter speed, but right now I'm accustomed  to only controlling one at a time. The camera is usually setting the other to get the right exposure automatically for me. So if I'm controlling both how do I know I have the correct exposure? I understand I need to use the metering in my camera but I'm not sure exactly how do do that.   First when should I be using each of the metering modes (Evaluative, Partial, Center weighted, or Spot)? These just change the area of the scene which is metered correct?  How do I know what the meter should read off a specific object? Obviously if I just happen to be shooting a 18% gray wall then it should be at zero, but that can't apply to everything? If I'm shooting a black cat and take a spot meter reading off of the cat then the meter should read less then zero right? But how do I know how much less then zero? Are there rules of thumb I can follow? I've ordered a couple gray cards with my new lens. So experimenting with those should help.  How often should I be changing these settings? Say I'm at a party indoors which is consistently lit. I should be able to set the aperture, shutter speed, and ISO and just forget about it unless the lighting changes correct? Does the same apply to outdoor scenes? I've been hesitant to use manual mode in the past because I felt like I was spending a lot of times messing with settings before each shot. But not I'm realizing that this is really only the case when the lighting changes, or I want a different style of photo such as a different depth of field.  Finally, does exposure change with distance to the subject? For example say I want to take a picture of a statue with correct exposure using a gray card. I'd place the card on the statue, and while being careful not the block the light on the card find the correct exposure by spot metering the card. If I were then to step back 20' to get the whole statue in frame would I still have the correct exposure? Question on showing a bijection between $\pi_1(X,x_0)$ and $[S^1, X]$ when X is path connected. I am trying to do this question taken from Hatchers algebraic topology and I am struggling to understand the notation and the concepts.  As far as I know $\pi_1(X,x_0)$ is the set of end point preserving homotopy classes of loops in X based at $x_0$ and a loop is just a path    $f:I \rightarrow X$ with $f(0)=f(1)$. The question says we can regard $\pi_1(X, x_0)$ as the set of basepoint preserving homotopy classes of maps $(S^1, s_0) \rightarrow (X, x_0)$.   This confuses me, does it mean the set of basepoint preserving homotopy class on maps $g:S^1 \rightarrow X$ which map loops in $S^1$ based at $s_0$ to loops in X based at $x_0$?  Then how can $\pi_1(X,x_0)$ be regarded as this set?  If someone could explain this it would be really useful I am extremely poor in solving a problem quickly, which leaves me doing badly in olympiads and other contests. But, if I just don’t give up on a problem, no matter how much time it takes, I usually end up solving it. To have a future in mathematics or physics, is it necessary for me to excel at contests, because these days children excelling at contests have an advantage over those who don’t (not complete advantage, but advantage nonetheless)? How to select kernel for SVM? How can I edit this trigger to only fire once? Is it possible to extend a tourist Schengen visa (12 more days)? My daughter applied at the Italian Consulate in Philadelphia, and they gave her two entries for 20 days (we thought it was for 20 days each entry). She was in Italy 12 days, then went to England for 1 week and flew to Venice to take a 10-day cruise. She couldn't make it because they said she has only 8 remaining days, but she still has a land tour already paid this week.  What can she do? Can she extend the Schengen visa for 12 more days? Right now, she is in Madrid, but next week she has to fly from Barcelona to Paris to start with the tour. What would happen if she decides to take the tour with the expired visa? She is a US permanent resident. A better proof for $\det(P) = \pm1$ if $P$ is an orthogonal matrix Comparing SVM and logistic regression Can someone please give me some intuition as to when to choose either SVM or LR? I want to understand the intuition behind what is the difference between the optimization criteria of learning the hyperplane of the two, where the respective aims are as follows:     SVM: Try to maximize the margin between the closest support vectors LR: Maximize the posterior class probability    Let's consider the linear feature space for both SVM and LR.  Some differences I know of already:   SVM is deterministic (but we can use Platts model for probability score) while LR is probabilistic. For the kernel space, SVM is faster (stores just support vectors) How to get an enum value from a string value in Java? Say I have an enum which is just public enum Blah {     A, B, C, D }  and I would like to find the enum value of a string, for example &quot;A&quot; which would be Blah.A. How would it be possible to do this? Is the  the method I need? If so, how would I use this? 18.04.01 Not available for server