Every possible means __________ to prevent air pollution, but the sky is still not clear.
| A．are being used |
| B．have been used |
| C．has been used |
| D．had been used |
Today the Red Cross provides a number of services for the public, such as helping people________, teaching first aid and providing blood.
| A．in need | B．in return | C．in preparation | D．in anger |
Everyone in the class is expected to________in the discussion.
| A．participate | B．attend | C．donate | D．declare |
Please post this letter in the post office nearby, and ______, I will get two tickets in the train station.
| A．in meantime | B．on the meanwhile | C．in meanwhile | D．in the meantime |
Many people are not________the danger of their children's bad habits, which lead to failing to make their dreams come true.
| A．well aware to | B．very aware of | C．aware that | D．well aware of |
A family of five is really a heavy burden, so we all have to work hard to________.
| A．find out | B．work out | C．help out | D．carry out |