题目内容
_________ program has been developed up to this date, but none of them are economical enough to be carried out now.
[ ]
A.
All
B.
Several
C.
Either
D.
Many a
答案:D
练习册系列答案
相关题目
题目内容
_________ program has been developed up to this date, but none of them are economical enough to be carried out now.
All
Several
Either
Many a