().
A.O
B.1
C.∞
D.2
参考答案:A
解析:用洛必达法则即可求得。
He pretended ______ the problem, but he ______.
A.to solve; lay
B.to have solved; lied
C.to have solved; laid
D.to solve; lied
一个正方形,如果边长增加5厘米,面积就增加25平方厘米.______.