-The frightening black clouds are gathering .lt______.
-Sure Let's go indoors,
| A． is to rain | B． rains | C． is going to rain | D． is raining |
22．Shylock, how can you hope for mercy yourself when you show _____．
| A．it | B．nothing | C．none | D．no one |
21．The doctor couldn’t answer the question _____ the patient could survive that night．
| A．if | B．that | C．whether | D．What |
20．---I got up at five this morning, I thought it was Friday．
---You _____ so early．It is Sunday today; you don’t have to go to work．
| A．mustn’t have got up | B．needn’t have got up |
| C．needn’t get up | D．mustn’t get up |
19．He says he really can’t _____ to wait another day．
| A．waste | B．afford | C．spare | D．Pay |
18．---I can’t recite the poem．
---Well, you are supposed _____ it many times yesterday evening．
| A．to read | B．to have read | C．reading | D．having read |