Implicit super constructor Event() is undefined
Java error: Implicit super constructor is undefined for default constructor
Should you use a plural verb if you refer to a fraction?     Nine tenths of the pillar have rotted away.   I think has should be used here, but I'm not sure. I’ve recently changed my ISP and noticed that I no longer can watch video sites like YouTube in real time; I need to wait for buffering first. On both ISPs, my speed was same 5 megabits per second.  I’ve checked normal download of files, and torrents, and they all work fine. Also, checked other video sites, same problem. Used other PC, same problem. Are submodules of finitely generated free modules always free? I don't believe it's true that all submodules of a finitely generated free module are free just based on results from google. Is there a canonical simple example of a finitely generated free module with a submodule that is not free? How can I remove the first line of a text file using bash/sed script? What to look for in the datasheet when choosing a MOSFET? Excuse me if the question is naïve. I am not a physicist.  Let's imagine formation of a black hole from a homogeneous collapsing star. At certain moment when enough of matter is inside of a small enough spherical area the event horizon starts to exist. When does the singularity start to exist and why?  The matter below the event horizon still continues to collapse towards the centre (e.g. in the reference frame of the falling matter). What are the necessary conditions for the singularity to appear?  I have found two similar questions but the answers did not really explain this problem to me: Hierarchical clustering with mixed type data - what distance/similarity to use? In my dataset we have both continuous and naturally discrete variables. I want to know whether we can do hierarchical clustering using both type of variables. And if yes, what distance measure is appropriate? Integrating $\frac{1}{\sqrt{ax^2+bx+c}}$ for $a<0$ I'm trying to integrate the function $\frac{1}{\sqrt{ax^2+bx+c}}$ for $a&lt;0$ and $b,c&gt;0$.   From a list of integrals of irrational functions from Wikipedia I know the result should contain arcsin or arcos, but I don't understand how to get there.  I've tried Euler's substitution and trigonometric substitution but I always stumble over the fact that $a$ is negative.  Can please someone help me? Where Can I Give Feedback on Ubuntu? I'm running Ubuntu 11.04 Beta 2. Is there a way, or a place, to give feedback on this system? Not file bugs, just give feedback. Index and length must refer to a location within the string XTerm only display part of some unicodes and Urxvt displays nothing In my case, (U)XTerm does display some unicodes, but only partially. For exmaple: for letters are: 𝒫φϕ𝒟. Here is a screenshot of UXTerm and Urxvt respectively   It seems that the problem is related to the letter space or letter length. By the way, everything is fine with gnome-terminal.  My current .Xresources file is: Xft.dpi:       120 Xft.antialias: true Xft.hinting:   true Xft.rgba:      rgb Xft.autohint:  false Xft.hintstyle: hintslight Xft.lcdfilter: lcddefault  XTerm*faceName:          Fixed XTerm*faceSize:          14 XTerm*reverseVideo:      false XTerm*selectToClipboard: true  UXTerm.vt100*faceName:          Fixed UXTerm.vt100*faceSize:          14 UXTerm.vt100*reverseVideo:      false UXTerm*selectToClipboard: true  URxvt.font:            xft:Fixed:pixelsize=18  URxvt.depth:                      32 URxvt.background:                 #222D31 URxvt*scrollBar:                  false URxvt*mouseWheelScrollPage:       false URxvt*cursorBlink:                true URxvt*background:                 black URxvt*foreground:                 grey URxvt*saveLines:                  5000  How to make XTerm and Urxvt to display those characters correctly? Is it possible? Pluralizing abbreviations where the noun is not the last word For abbreviations - both acronyms and initialisms - where the last word in the abbreviation is the noun, I'm accustomed to adding an 's' with no apostrophe (e.g. ATMs), as described in the answer to this question:   But how do you pluralize abbreviations where the noun is not the last word? E.g. 'Point of Presence' (POP)  I can see how 'POPs' could read 'Point of Presences', when the intention is 'Points of Presence.' Why is the application of probability in QM fundamentally different from application of probability in other areas? What is the easiest way to export just the selected objects in Illustrator? The title says it all, I want to know what the simplest way to export the selected objects.  In Inkscape, there is a menu option called export selected which does just this.    The aforementioned option lets you export the selection as a composite image or as a batch of individual images.  Both would be nice, but in this scenario I want to export the selected objects as a single image.  I can already create a new document, and paste in the selected items.  I am looking for a way that is easier than this.  How can I save / output / export only the objects I currently have selected, to an image file, in Adobe Illustrator CS5? How do I arrange selected vertices into a circular formation quickly?  The other answers does not have the same title as my question. My question is direct and simple for younger beginner to search for results. Send Ctrl+Alt+F1, Crtl+Alt+F7 into VirtualBox I deleted the "/etc/passwd" file and cannot log in Can sudo be reinstalled after being removed? How to do relative imports in Python? Interface vs Abstract Class (general OO)