[单选题]A.(1)(2)B.(2)(3)C.(2)(3)(4)D.(1)(2)(3)(4)

[单选题]A.(1)(2)B.(2)(3)C.(2)(3)(4)D.(1)(2)(3)(4)

[单选题]A.(1)(2)B.(2)(3)C.(2)(3)(4)D.(1)(2)(3)(4)

[单选题]A.1∶3∶1B.2∶3∶1C.2∶2∶1D.1∶3∶3

[单选题]A.Needs of the readers all over the world.B.Causes of the public disappoint

[单选题]A.分子中所有的原子共面B.1molEGC与4molNaOH恰好完全反应C.易发生加成反应，难发生氧化反应和取代反应D.

[单选题]A.分子中所有的原子共面B.1molEGC与4molNaOH恰好完全反应C.易发生加成反应，难发生氧化反应和取代反应D.

[单选题]A.图(a)总净功为负，图(b)总净功为正，图(c)总净功为零B.图(a)总净功为负，图(b)总净功为负，图(c)总净功为正C.图(a)总净功为负，图

[单选题]A.B.C.D.

[单选题]A.线环向右平移B.线环向上平移C.线环向左平移D.磁场强度减弱