问题
选择题
Man-made-satellites______ into space by many countries.
A．was sent up
B．is sent up
C．have been sent up
D．has been sent up
答案
答案：C
搜题请搜索小程序“爱下问搜题”
Man-made-satellites______ into space by many countries.
A．was sent up
B．is sent up
C．have been sent up
D．has been sent up
答案：C