Scientists from different countries are trying to_____ a good way to solve the energy problem.
| A．keep up with | B．come up with |
| C．catch up with | D．meet up with |
--Have you seen Mr. Black? I have something important to tell him.
--Don’t worry. Let me ____________his phone number in my telephone book.
| A．look after | B．look like |
| C．look for | D．look up |
My father likes smoking. He often says that giving up smoking is the easiest thing in the word. I know because I________ it thousands of times.
| A．have done | B．am doing |
| C．will do | D．do |
--What are you going to do tonight, Cindy?
--I’m not sure. I __________go to see a movie with my friends.
| A．must | B．should |
| C．might | D．have to |
__________ it’s very difficult, remember not to give up until the last minute.
| A．Until | B．Unless |
| C．Although | D．Since |
--Shall I close the door?
--No. Just _____it open.
| A．offer | B．try | C．push | D．leave |