Many Europeans ________ the continent of Africa in the 19th century.
A. exploded
B. exposed
C. explored
expanded
Various _____ of electric fans are now on display in the shop windows.
| A．boxes | B．sizes |
| C．standards | D．brands |
E-mail is a valuable _____ for college students at any level.
| A．hand | B．tool |
| C．product | D．data |
Lin Fang won first prize in the English contest and her efforts at last _____ .
| A．pay back | B．paid off |
| C．paid for | D．paid down |
People _____ a long queue to buy the ticket for the concert.
| A．quitted | B．crowded |
| C．formed | D．stood |
—Which one of these shirts would you like?
—__________. Either is OK.
| A．I don't mind | B．I'm sure |
| C．No problem | D．Go ahead |