_______ difficult and challenging the task may be, we must finish it on time, because there is a possibility _______our work will go down in history.
| A．Whatever; that | B．However; as |
| C．Whatever; which | D．However; that |
Both rice and wheat _____ grown in our country.
| A．is |
| B．are |
| C．was |
| D．were |
Mathematics _______ the language of science.
| A．are |
| B．are going to be |
| C．is |
| D．is to be |
Stories of the Long March _______ popular with the young people now.
| A．is |
| B．was |
| C．are |
| D．were |
Three million tons of coal ______ every year in the city.
| A．is exploited |
| B．are exploited |
| C．had exploited |
| D．have exploited |
There _____ a lot of rubbish on the floor so I asked Mary to sweep _____ up.
| A．were; it |
| B．are; them |
| C．was; it |
| D．is; them |