单项选择题

Tough as the task was, we ______ finish it ahead of time and therefore we were highly praised for it.

A．would
B．had to
C．were able to
D．must
<上一题 目录 下一题>
热门 试题

单项选择题
Carbon dioxide ______ from burning fuels is the most common of the so-called greenhouse gases.
A．producing
B．having been produced
C．to be produced
D．produced
相关试题