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
【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