问题 选择题
According to the companies' websites, the number of active QQ users in China has reached 1 billion, while Qihoo 360 also claims ______ at least 300 million users before June 2010.

A. to have
B. to have had
C. having
D. having had
答案

答案:B

单项选择题 A1型题
单项选择题