you may have , you should gather your courage to face the challenge .
| A．However serious a problem | B．Whatever serious a problem |
| C．However a serious problem | D．No matter how a serious |
Leaves are found _______ all kinds of trees, but they differ greatly ________ size and shape.
| A．in; on | B．in; from | C．on; by | D．on; in |
To save class time, our teacher has ________ students do half of the exercises in class and complete the other half for our homework.
| A．we | B．us | C．our | D．ours |
Now an increasing number of middle school students go abroad for further study at their own ________, trying hard to realize their dreams.
| A．price | B．cost | C．expenses | D．pay |
Darwin counted 225 flowering plants, ________ he collected and brought home 193.
| A．that | B．in that | C．of which | D．all of which |
The government has taken some measures to reconstruct the earthquake-hit areas, but it must be some time ________ everything returns to normal.
| A．since | B．after | C．unless | D．before |