.
Mary is a(n) _______ customer, so the waiter knows her likes and dislikes.
| A．usual | B．ordinary | C．common | D．regular |
Willpower is a kind of quality, _____ is _____ it takes to do anything well.
| A．that; which | B．which; what | C．that; that | D．which; which |
I was so familiar with him that I recognized his voice _____ I picked up the phone.
| A．as | B．after | C．the instant | D．while |
It’s reported that the police will soon ____ the case of two missing children.
| A．look into | B．look after | C．look upon | D．look out |
Tom is keen _____ surfing the Internet in his spare time.
| A．at | B．on | C．to | D．in |
The students were completely _____ in their reading.
| A．absorbing | B．being absorbed | C．to absorb | D．absorbed |