Jackson has got to be crazy ________Chinese culture since he visited China last time.
| A．about | B．with |
| C．for | D．at |
_______ their service, the workers of the hotel are active in learning English.
| A．Improving | B．To improve |
| C．Improve | D．Having improved |
It was about 600 years ago _____ the first clock with a face and an hour hand was made .
| A．that | B．until | C．before | D．when |
—Which of these two electronic dictionaries do you like better ?
—_____ . They are both expensive and of little use .
| A．Neither | B．All | C．Both | D．None |
The weather turned out to be very good ,_____ was more than we could expect .
| A．what | B．which | C．that | D．it |
What you should remember is that we should always keep____ in an emergency .
| A．still | B．calm | C．quiet | D．silent |