27．After his wife died, he kept himself _____ from other people and the outside world,
| A．set off | B．cut off | C．put off | D．taken off |
23. In some countries, _______ are called “public schools” are not owned by the state.
| A．that | B．which | C．as | D．what |
22. “How long do you suppose it is _______ he left for Japan?” “No more than half a month.”
| A．when | B．before | C．after | D．since |
21. Mr Zhang is mild in character. He never shouts ____ he is very angry.
| A．if | B．even | C．though | D．even when |
20. John shut everybody out of the kitchen _______ he could prepare his grand surprise for the party.
| A．which | B．when | C．so that | D．as if |
19. _______ rich one may be there is always something one wants.
| A．whatever | B．Whenever | C．however | D．Wherever |