【题目】It's all right to drink coffee______，but don't let it become a habit for it is not good for your sleep.
A.completely
B.frequently
C.occasionally
D.generally

【答案】C
【解析】A．completely完全地，彻底地；B．frequently频繁地；C．occasionally偶尔地； D．generally一般而言；句意：偶尔(occasionally)喝点咖啡没关系，但是不要让它成为习惯因为它对睡眠不好。根据句意，故选C。