He is only too ready to help others, seldom, ____, refusing them when they turn to him.
| A．if never | B．if ever | C．if not | D．if any |
The sentence needs _______ once more.
| A．explained | B．explaining | C．being explained | D．to explain |
The computer centre, _______ last year, is very popular among the students in this school.
| A．open | B．opening | C．having opened | D．opened |
Rather than _______ on a crowded bus, he always prefers _______ a bicycle.
| A．ride; ride | B．riding; ride | C．ride; to ride | D．to ride; riding |
_______a reply, he decided to write again.
| A．Not receiving | B．Receiving not | C．Not having received | D．Having received not |
There seemed nothing else to do but ______ a doctor.
| A．to send for | B．to call for | C．send for | D．to call in |