Only after he realized the significance of mastering two languages __________ English carefully.
| A．did he set about learning | B．did he set out learning |
| C．had he set about learning | D．had he set out learning |
We got to the top of a mountain _________ we can see the whole city.
| A．at where | B．from there | C．from where | D．there |
He rarely switches on to hear any of the classical music he claims to be so keen ____.
| A．to | B．on | C．by | D．into |
______ exceptionally heavily might railway services be temporarily dislocated (扰乱).
| A．If only it snowed | B．Only in case it snows | C．Only were it to snow | D．Only when snow |
Jack is late again. It is _______ of him to keep others waiting.
| A．normal | B．ordinary | C．common | D．typical |
I hope I will not be called on in class as I’m not yet ____ prepared.
| A．attentively | B．readily | C．actively | D．adequately |