【题目】As autumn announces its coming, the trees _____ turn yellow, which means winter will draw near too.
A.freely
B.actually
C.gradually
D.frequently

【答案】C
【解析】句意：随着秋天的到来，树逐渐变黄了这意味着冬天将临近了。A. freely“自由地”；B. actually“实际上”；C. gradually“逐渐地”；D. frequently “频繁地”。根据句意选C。