3.听下面一段材料,回答16至18题 16.How often does Jack eat vegetables? A.Hardly ever. B.Every day. C.Sometimes. 17.How many times does Jack exercise? A.More than three times a week. B.Twice a week. C.Less than three times a week. 18.How does Jack like coffee? A.Very much. B.Not at all. C.A little.