从表达的具体手段上说，公文不可以用（）。 ["修辞手法","文学手法","比喻手法","拟人手法","幽默手法"]
When a pushing vessel and a vessel（）ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel. ["is pushed","being pushed","was pushed","be pushed"]
本田、丰田、别克属于中档轿车的（）。 ["A.品牌竞争者","B.行业竞争者","C.需要竞争者","D.消费竞争者"]
现行储蓄利率均为（）。 ["A.日利率","B.月利率","C.季度利率","D.年利率"]
各部软化点的不同，煤沥青一般可分为哪几种？
产前诊断的定义是什么？
