Last year the number of studects who graduated with a driving licence reached 200,000, a(n) ________of 40,000 per year.
| A．average | B．number | C．amount | D．quantity |
—Guess what？I came first in that contest.
—Great！You ________ a lot during the past two weeks.
| A．must practise | B．should practise |
| C．should have practised | D．must have practised |
—Where will you start your work after graduation?
—Mum，it's not been decided yet.I ________ continue my study for a higher degree.
| A．need | B．must | C．would | D．might |
—Why do you look so puzzled?
—Oh，I ________ over a most difficult maths problem.
| A．thought | B．have thought |
| C．am thinking | D．think |
—Peter！Let's hurry.The boss is coming.
—Oh，I was afraid that we ________ her.
| A．miss | B．had missed |
| C．will miss | D．have missed |
The past two years ________ a sharp rise in oil price，which adds to the burden of auto transportation industry.
| A．witnessed | B．has witnessed |
| C．is witnessing | D．witnesses |