sosuddenthattheenemyhadnotimetoescape.A.didtheattackB.wastheattack.sosuddenthattheenemyhadnotimetoescape.A.didtheattackB.wastheattack.为什么选B答案,什么时候用did?

Question

so sudden _ that the enemy had no time to escape .A.did the attack B.was the attack.
so sudden _ that the enemy had no time to escape .
A.did the attack B.was the attack.
为什么选B答案,什么时候用did?

Answer 1

B.was the attack.为正确选项.
这是个倒装句,还原回普通句是,The attack was so sudden that the enemy had no time to escape.很明显,前半句是个主系表结构,句子已经有了was,不能再用did.