David apologized for ________ to inform me of the change in the plan.
| A．his being not able | B．him not to be able |
| C．his not being able | D．him to be not able |
---How was Mary’s performance?
---Oh, pretty good. I was quite __.
| A．admired | B．interested | C．impressed | D．encouraged |
An idea came to him ___ he might do the experiment in another way.
| A．which | B．when | C．what | D．that |
It is so wet there that the trees are extremely tall, some ________ over 90 metres.
| A．are measured | B．measuring | C．measured | D．measure |
Rather than ___ on a crowded bus, Tom always prefers __ a bicycle.
| A．ride; ride | B．riding; ride | C．ride; to ride | D．to ride; riding |
Perseverance is a kind of quality --- and that’s ________ it takes to do anything well.
| A．why | B．that | C．which | D．what |