盐酸哌替啶为（）
A.半合成镇痛药
B.合成镇痛药
C.具黄嘌呤母核的中枢兴奋药
D.兴奋延髓的中枢兴奋药
E.苯乙胺类的拟肾上腺素药
参考答案：B
1. 去年你弟弟去哪儿度假了? 他们去了纽约.
—_____ _____ your brother go on vacation last year?
—They _____ to New York City.
2. 昨天上午你看望你的叔.
—_____ you _____ your uncle yesterday morning?
—_____, I _____.
3. He went to the mountains yesterday. (对划线部问)
_____ _____ he _____ yesterday?
4. She studied for exams at home last weekend. (对划线部分提问)
_____ _____ she _____ for exams last weekend?
玉米正常储存年限是几年？
