问题
选择题
. Getting to other planets or to the moon _____ many problems.
A．involve
B．involves
C．involving
D．to involve
答案
答案：B
搜题请搜索小程序“爱下问搜题”
. Getting to other planets or to the moon _____ many problems.
A．involve
B．involves
C．involving
D．to involve
答案：B