题目

Mother was cooking in the kitchen________ Jack was watching TV in the room.A.if B.as C.when D.while 答案：【答案】D【解析】句意：当杰克正在房间里看电视时，妈妈正在厨房做饭。考查连词辨析。if是否，如果；as当……时，随着；when当……时；while当……时，根据语境可知，应该是当……时，排除A，由主句Mother was cooking in the kitchen和从句Jack was watching TV in the room是两个同时进行的动作，主句和从句同时10、下列化学方程式中，错误的是（　　）A、Ca（OH）2+CO2=CaCO3↓+H2OB、KOH+H2SO4=K2SO4+H2OC、2NaOH+CuSO4=Na2SO4+Cu（OH）2↓D、Ca（OH）2+2HCl=CaCl2+H2O