Science and technology have ____in important ways to the improvement of agricultural production.
| A．attached | B．assisted | C．contributed | D．witnessed |
He had decided to give it up , but on____ second thoughts he decided to try___
third time.
| A．the; a | B．/ ; / | C．a; a | D．/ ; a |
.As is known to all,____ tiger is in____ danger of dying out.
| A．a; a | B．the; / | C．a; / | D．the; the |
British people always talk about wether.
| A．the; the | B．/ ,/ | C．/; the | D．the; / |
He is doctor at all. Don’t trust him.
| A． no | B． not | C．any | D．a |
He is a member of our .
| A．brain power | B．brains power | C．brain powers | D．brains powers |