题目
1.19 If a better material had been used the efficiency of the machine ( ) much increased.○ would have been ○ has been○ had been ○ will be
1.19 If a better material had been used the efficiency of the machine ( ) much increased.
○ would have been
○ has been
○ had been
○ will be
题目解答
答案
has been;句意为:“如果用了更好的材料，这一部分的强度就会增加。本题考查虚拟语气的用法。”表示对过去的虚拟，从句一般用过去完成时，主句用“would have done…"，本句要用被动语态。故答案为：has been.