【C5】A．changeB．warningC．billD．cigarettes

A．changeB．observeC．improveD．meet

The author winds up the passage with a ______ note.A．cautiousB．warningC．positiveD．humorous

【C4】A．changeB．alterC．varyD．differ

【C6】A．changeB．mistakeC．differenceD．mark

【C2】A．changeB．decisionC．reductionD．relation

【C6】A．changeB．notesC．checksD．bills