Having lived in China for 8 years, Helen has a good ____________ of both English and Chinese.
| A．ability | B．guidance | C．command | D．program |
She found her calculator _____ she lost it.
| A．where | B．when | C．in which | D．that |
For breakfast, he only drinks juice from fresh fruit____ on his own farm.
| A．grown | B．being grown | C．to be grown | D．to grow |
Leaves are found on all kinds of trees,but they differ greatly_____ size and shape.
| A．on | B．from | C．in | D．by |
When the H1N1 virus____ at first in Mexico, no one had the least idea that it would spread so rapidly throughout the world.
| A．broke off | B．broke down | C．broke out | D．broke away |
It____ Tom that parked the car here, as he is the only one with a car.
| A．may be | B．can be | C．must have been | D．should have been |