I have a Lenovo laptop running Ubuntu 18.10 with kernel 4.19.0-041900-generic.  Only Ubuntu is installed.  When I turn on the laptop it directly boots into Ubuntu. I want to go to Advanced Options to boot a different kernel.  Pressing Shift or Esc is not working for me.
I read here at  that holding Shift during boot can bring up the GRUB menu. However I try holding one or the other Shift keys, tapping, tapping then holding, nothing works. Am I missing something? How does one access the GRUB menu during boot time?   No dual boot here, just standard Lubuntu 14.04 install.
How can I make a copy of a material? Installing VMware on 18.04: Failed to build vmmon True or false: {{∅}} ⊂ {∅,{∅}} Typo in First Posts queue If you go to the First Posts review queue, and if there's an answer in the queue and if you hover with your mouse over "No Action Needed", then you get a tooltip "this answers seems to be valid":  But it should be "this answer seems to be valid". Sarrus Rule with LaTeX Is there a way to create a new command with 9 arguments ({a_{11}},{a_{12}},{a_{13}},{a_{21}},{a_{22}},{a_{23}},{a_{31}},{a_{32}},{a_{33}}) that has as output a matrix with the Sarrus Rule? For instance: to obtain     just use the command that we will call sarrus:  \sarrus{-k}{k-1}{1}{0}{k-1}{k}{2}{0}{1}.   If it is possible i want to use the command sarrus in math mode just like matrix for istance. Are all simple left modules over a simple left artinian ring isomorphic? Some areas of the mesh are dark (Shadow artefacts) I've been modeling a hermit crab and I don't know why but some areas of the mesh are really dark on some spots, like the legs and the claws.   I hope you can help me fix it. How to shift EXIF date/time created by time in days, hours, minutes? Say if I define a power series over some arbitrary field $F$ as   $$a = \sum^{ \infty }_{i = 0} a_{i} X^{i} $$  Then can I say:  $$ab = \sum^{ \infty }_{i = 0} \sum^{ \infty }_{j = 0} a_{i} b_{j} X^{i + j} $$ Is it possible to combine processing power of 2 computers? Here are a few questions, I wish you could enlighten me.   Is it possible to combine processing power of 2 computers? How do I do it? I want to writing the matrix on the arrow from X to Y 3x3 type, from Z to Y 3x2 type ; How to typeset row operations on augmented matrix I would like to typeset row operations on a augmented matrix, but the "gauss"-package does not seem to support the vertical line just before the last column, any way to do this?  Thanks! How do I shuffle cards for a card game? I am trying to develop an card game for Android Can anyone suggest me how to write code for effectively shuffling the playing cards? Export Windows 7 search results to a text file How to use IDM on Mozilla Firefox Quantum I want to use Internet Download Manager for downloading on Firefox. According to this  it can be done with the extension called Flashgot. But Flashgot does not work on new Firefox Quantum. However, I found  that can be used to interrupt browser's downloading jobs by redirecting these jobs to an external download manager like Internet Download Manager (IDM). But I don't know how to integrate IDM with this new extension. I wrote IDM's location (/.wine/drive_c/Program Files (x86)/Internet Download Manager/IDMan.exe) in the box that says "Path to the executable" but when I try to download something, an error is appearing.     The preference page of the extension        The error that is appearing while trying to download files     How can I make it work? Thanks beforehand! Hi I'm traveling to Uzbekistan and have 12 hours layover in Seoul via Korean Airlines. Do I need a visa to go out of the airport for sightseeing? I'm a Philippine passport holder. Why does unequal amounts of RAM in each slot decrease performance? describes the RAM specifications for many of the MacBook laptops. In the section for my laptop (13" Pro Late 2011), it says:     Additional Notes: For best performance, fill both memory slots, installing an equal memory module in each slot.   This isn't the first time I've heard of this phenomenon, and it's definitely not specific to Apple.   Why is this the case? Other than the obvious decrease in available memory, why would it be worse to run with 6GB (1x4GB + 1x2GB) than with 8GB (2x4GB)? What would you call a word that doesn't exist in or translate well into another language? I've run into this situation several times, being a native Spanish speaker.   There are some words you just can't translate into another language. Is there a particular word to describe this?  I'm not refering to idioms.  Also, if its a noun, people tend to use them by surrounding them in quotes. Is this appropiate?  Example:     I arrived at around 5 pm and had some quesadillas.   Edit:  I also meant to cover words that exist in English, but cannot be translated into another language.   Example:      There isn't a word for "drive-thru" in your language. Find $x$ in   $$ \Large 2 = x^{x^{x^{\:\cdot^{\:\cdot^{\:\cdot}}}}}$$   A trick to solve this is to see that $$\large 2 = x^{x^{x^{\:\cdot^{\:\cdot^{\:\cdot}}}}} \quad\implies\quad 2 = x^{\Big(x^{x^{x^{\:\cdot^{\:\cdot^{\:\cdot}}}}}\Big)} = x^2 \quad\implies\quad x = \pm \sqrt{2} $$  Are these solutions correct? If not, why? If yes, are there other solutions?    PS: An extension of this discussion can be found in How to tell Google that I have changed my website URLs? I have done major updates to my website, and renamed all my URLs.  How can I tell Google that I have renamed these URLs and let Google refresh its index?  My website URL: http://www.pndmasr.com/  My sitemap: http://www.pndmasr.com/sitemap.xml  I have uploaded my sitemap via Google Webmaster Tools many times.  However, every time I search Google for "pndmasr", I still get results with old pages. I have waited more than 3 days but the problem remains. Any suggestions?  Is there a problem with my sitemap?