Question

At last the mother had no choice but ___________ her son herself, though she was quite busy．

A．to pick up

B．pick up

C．picking up

D．picked up

Answer 1

A

固定结构：had no choice but to do sth 别无选择只有…。 最后妈妈别无选择只有背起孩子尽管她很忙。