【C5】A．easyB．relaxedC．simpleD．ready

【C17】A．senseB．sureC．clearD．ready

A．easyB．ableC．likelyD．apparent

【C19】A．easyB．effortlessC．difficultD．formidable

It is _______ to tell which is earth and which is sky.A: enough easyB: easily enoughC:

【C11】A．easyB．simpleC．longD．difficult

【C9】A．easyB．criticalC．difficultD．tough