现将X改为100,Y改为200,下列说法正确的是( )
Microsoft ended support for Windows XP after April 8, which _______a major operating system for some Chinese computer users, and advised users to upgrade to Windows 8.1.
某口袋中有10个红球、8个黄球和若干个白球,将它们充分摇匀后从中摸出一球,小明通过多次摸球试验后,发现摸到白球的频率稳定在0.4左右,则口袋中大约有____ 个白球.