—If you want to stay healthy,you must give up smoking.
—Sure,I will. Smoking is _____ my health.
be good for 对……有好处；be harmful to 对……有害；be full of 充满；be used to 习惯于。结合本题语境可知，吸烟对健康有害，故答案为 B。
My friend _____ many postcards since he went to Paris.
本题考查动词时态。根据 since he went to Paris 可知，要用现在完成时，故答案为 D。
I think Kate is better at playing basketball because she is _____ than Jenny.
本题考查形容词的词义理解。根据题干中的“凯特更擅长打篮球”可推断，她比珍妮“更强壮”，故答案为 C。