【C2】A．ifB．whenC．althoughD．since

【C8】A．ifB．whenC．whileD．as

【C17】A．IfB．WhenC．BeforeD．As

材料题请点击右侧查看材料问题 查看材料A.ifB.whenC.becaus

_____ there is smoke, there is fire.A: IfB; WhenC; Where

【C8】A．whereB．whenC．althoughD．however

【C2】A．only ifB．much asC．long beforeD．ever since