【单选题】喷射混凝土施工时,为防止混凝土因自重而脱落,可掺用适量______。
【单选题】The old professor has three sons,________are doctors.
【判断题】活塞连杆组的主要零部件有:活塞、活塞环、活塞销、连杆、连杆盖、连杆瓦、连杆螺栓等
【简答题】A.Grade all the homework. B.Clean the professor's office. C.Help the professor in the classroom. D.Sort all the documents.
【判断题】活塞连杆组的主要零部件有:活塞、活塞环、活塞销、连杆、连杆盖、连杆瓦、连杆螺栓等。( )
【简答题】A.The professor has graded the paper. B.The professor has been in the meeting all week. C.The professor hate, to grade the paper. D.The professor has read his paper on the meeting.
【单选题】Professor Zhang gave all the textbooks to all the pupils, except _____ who had alreadytaken them.
【简答题】A.Grade all the homework. B.Clean the professor's office. C.Help the professor in the classroom. D.Sort all the documents.