两数相加，一个加数增加6，另一个加数减少8，它们的和起什么变化（）
A．减少到2
B．增加了2
C．等于2
D．减少了2
参考答案：D
— _________ has Liu Xiang taken part in world’s competitions of 110-metre hurdles?
— I’ve no idea. Let’s find it out on the Internet.
A．How often
B．How many times
C．How much time
D．How much
安息角
