In aerospace devices the weight of the necessary power producing equipment is _____.
| A．vital | B．possible | C．capable | D．reliable |
He did not regret saying what he did but felt that he____________ it differently.
| A．could express | B．would express |
| C．could have expressed | D．must have expressed |
He asked ______ for the violin.
| A．did I pay how much | B．I paid how much |
| C．how much did I pay | D．how much I paid |
Don't sit there ________ nothing. Come and help me with this table.
| A．do | B．to do | C．doing | D．and doing |
He made another wonderful discovery, _____ of great importance to science．
| A．which I think is | B．which I think it is |
| C．which I think it | D．I think is |
One of the best ways for people to keep fit is to______ healthy eating habits.
| A．grow | B．develop | C．increase | D．raise |