A large number of engineers ___ to Africa by our government to help the people there every year.[ ]

A. have sent        

B. will send          

C. are sent        

D. was sent

2013年6月11日，我国成功发射神舟十号载人飞船。飞船入轨后，按照预定程序首次开展（）来了航天员

A.太空授课活动

B.手控交会对接

C.自动交会对接

D.出舱行走作业