【C8】A．effectiveB．efficientC．affectionateD．moved

【C8】A．sufficientB．efficientC．effectiveD．sufficiency

【C20】A．instructiveB．efficientC．beneficialD．profitable

【C9】A．effectiveB．passiveC．relativeD．expressive

A．effectiveB．importantC．efficientD．special

【C3】A．proficientB．efficientC．sufficientD．elaborate

【C16】A．effectiveB．substantialC．preliminaryD．contemporary