流行病学主要研究的问题是
A．疾病分布及影响分布的因素
B．疾病的病因
C．疾病的防治措施
D．流行病研究方法
E．以上均是
参考答案：E
句型转换。
1. He would like to join the music club. (同义句)
He ______ ______ ______ the music club.
2. She can sing and dance. (否定句)
She ______ _______ _______ dance.
3. Li Lei can play the violin. (一般疑问句)
______ Li Lei _____ the violin?
4. She wants to join the music club. (就划线部分提问)
______ ______ ______ _____ _____ to join?
5. My sister can swim very well. (就划线部分提问)
______ ______ ______ sister swim?
常配伍甘遂、大戟、芫花等峻下之剂，具有缓和药性，保护脾胃功效的药物是（）
A.甘草
B.大枣
C.饴糖
D.白术
E.山药
