Exactly______ the potato was introduced into Europe is uncertain, but it was probably around 1565.
| A．whether | B．why | C．when | D．how |
Is thisthe research center _____you visited thelablast year ?
| A． which | B． the one | C．that | D．where |
Don’t believe him .He is just _____ an exc
use .
| A．making out | B．making up of | C．making up | D． making from |
-Would you mind if I take the seat?
- .
| A．Yes, sit down, please | B．Surely, never mind |
| C．No, not at all | D．No, you can’t take it |
The bell rang and came in Mr.Brown, a book in his hand. Then the class began.
| A．for | B．when | C．with | D．while |
In the past 5 years a great deal of money _____ improving the environment of the school.
| A．is spent | B．has been spent | C．was spent | D．had been spent |