The professor could hardly find sufficient grounds _____his arguments in favor of the new theory.
| A．to be based on | B．to base on | C．which to base on | D．on which to base |
The man ______ talked to you just now is an engineer.
| A．who | B．whose | C．which | D．what |
All ______ we need is to be supplied with food and clothing.
| A．what | B．that | C．which | D．whom |
Play, often seen as _______ activity for kids ,is still important in _____ development of teenagers.
| A．the ; the | B．an; the | C．an ;不填 | D．the；不填 |
The oil price has _______ a lot these days because of the war .
| A．gone back | B．gone up | C．gone over | D．gone out |
The foreign friends you referred to _______ looking forward to _______around our university.
| A．are ; being shown | B．being ;being shown | C．being ; showing | D．are ;be shown |