【C6】A．seldomB．alwaysC．oftenD．never

A． onceB． neverC． oftenD． usually

【C18】A．merelyB．alwaysC．mainlyD．almost

【C12】A．seldomB．sometimesC．usuallyD．never

【C2】A．SeldomB．AlwaysC．FrequentlyD．Rarely

A．neverB．seldomC．oftenD．always

【C3】A．seldomB．alsoC．yetD．even