基础检测
Ⅰ.词性转换
1．She could find no reasonable explanation for the ________(disappear) of the money in the locked safe.
2．We recommend that you keep your seat belt ________(secure) fastened and visible at all times.
3．The problem to be discussed at the meeting next week is of great ________ (important)．
4．________(protect) measures are necessary if the city's monuments are to be preserved.
