单选题
The United States (has sent) several (spacecrafts) into orbits (around the earth) and has collected a lot of (information).
A. has sent B. spacecrafts C. around the earth D. information
A
B
C
D
【正确答案】
A
【答案解析】
改为sent。一般过去时陈述过去发生的事情。
提交答案
关闭