There was nothing we could do that day him down but him in the house.A. calm lockB. to

问题补充：

There was nothing we could do that day him down but him in the house.

A. calm, lock

B. to calm, to lock

C. calming, locking

D. to calm, lock

答案：

A. calm, lock

B. to calm, to lock

C. calming, locking

(答案→)D. to calm, lock

解析：考查不定式用法和固定搭配。本句中的不定式表示的是目的状语；第二空but前面如果有动词do的某种形式，就要省略不定式符号to,如果没有动词do的形式，不定式符号to就不能省略。句意：那一天为了让他镇定下来，除了把他锁在房子里我们无计可施。But前面有do，故省略不定式符号to。故D正确。