He must be helping the old man to water the flowers，________？
| A．is he | B．isn't he |
| C．must be | D．mustn't he |
It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.
| A．process | B．attention | C．measure | D．part |
The author of the report is well _____ with the problems in the hospital because he has been working there for many years.
| A．acquainted | B．informed | C．enlightened | D．advised |
With the change of the economic foundation the entire immense superstructure is _____ rapidly transformed.
| A．anything but | B．more or less | C．at large | D．any more |
Even if they are on sale, these refrigerators are equal in price to, if not more expensive than, _____ at the other store.
| A．anyone | B．the others | C．that | D．the ones |
Her skirt had been so _____ in packing that she had to iron it before going out.
| A．faded | B．torn | C．dirty | D．crushed |