As many people do, you often pretend ________ work when actually you are just wasting time online.
A:doing
B:to do
C:to be doing
D:to have done
如图,在函数y1=k1x(x<0)和y2=k2x(x>0)的图象上,分别有A、B两点,若AB∥x轴,交y轴于点C,且OA⊥OB,S△AOC=32,S△BOC=272,则线段AB的长度是( )
在点燃条件下,甲与乙反应的微观示意图如下.下列说法正确的是( )
如图,OA⊥OB,∠1=35°,则∠ 2的度数是( )