问题补充：
—Do you know who invented Chinese chess?—Sorry. I don’t know. Let’s the Internet .
A. search; find out it
B. to search; to find it out
C. to search; to find out it
D. search; to find it out
答案：
A. search; find out it
B. to search; to find it out
C. to search; to find out it
D. search; to find it out
解析：考查let sb. do sth.和to do作目的状语以及动词加副词结构。让我们上网去搜搜。故选D
