.
A proper approach to ________ your learning efficiency is of great significance to every student.
| A．improving | B．improve | C．be improving | D．having improved |
— I rang you up last night, but nobody answered.
— Oh, I usually ________ off my phone at about 9:00 p.m.
| A．switched | B．have switched |
| C．switch | D．had switched |
There are two rooms in the apartment, ________ serves as a kitchen.
| A．the smaller of them | B．the smallest of which |
| C．the smaller of which | D．smallest of which |
After a second thought, Bill ________ a better idea of how to solve the problem.
| A．put up with | B．came up with |
| C．kept up with | D．mixed up with |
The number of new energy vehicles in China’s cities ________ to reach 39,000 by the end of this month, according to Wan Gang, Chinese Minister of Science and Technology.
| A．are expected | B．is expecting |
| C．are expecting | D．is expected |
John wants to see me now, but I have so much work on hand that I would rather he ________ tomorrow than today.
| A．should come | B．will come | C．is coming | D．came |