低压电器触头常见故障有触头过热、触头磨损和（）三方面。
参考答案：触头熔焊
—He has got ________ idea. He lets his sister go with him.
—That's ________ good idea. [ ]
A. a; an
B. a; a
C. an; a
D. an; an
一切险的责任范围涵盖所有险别，包括偷窃，提货不着险及战争险。（）
