下列哪项不是吗啡镇痛药成瘾的精神症状
A.情结果低落、消沉、易激惹
B.痴呆
C.用成瘾药后情绪高涨、活跃
D.记忆力下降
E.人格改变
参考答案:B
—I like your new leather boots!
—Thanks.I had to try on almost a dozen pairs ______ I decided to get them.
A.as
B.when
C.after
D.before
裂解气压缩机停车后乙烯精馏塔只能停止运行。