在线名词解释大全
专业、全面、易懂的全领域名词百科
首页
>
实用英语语法
>
详细
_________noelectroniccomputers,theycouldhavebeennosatellitesrockets.
题型:单选题
选项
A.
Had there been
B.
If there were
C.
Should there be
D.
If there are
正确答案: