Market economy is a competitive economy, ______ I think, suppliers, producers and dealers should obey market rules and develop cooperative relation based on mutual benefits.
| A．that | B． which | C．where | D．how |
She had just finished her homework ______ her mother asked her to practise playing the piano yesterday.
| A．when | B．while | C．after | D．since |
The professor got a disease in blood for the _______ of fresh vegetables and fruit.
| A．snake | B．lack | C．ignorance | D．minority |
---- Do give me a call when you arrive in the city, Henry.
---- I won’t forget. See you later.
---- ____________.
| A．Have a nice trip | B．With pleasure | C．Don’t mention it | D．It’s kind of you |
The manager, ______his factory’s products were poor in quality, decided to give his workers further training.
| A．knowing | B．known | C．to know | D．being known |
---- Have you seen Mike these days?
---- Yes. I saw him the day before yesterday. In fact, I ______ him for three years.
| A．didn’t see | B．haven’t seen | C．hadn’t seen | D．don’t see |