问题
单项选择题
临床上用于防治疾病中即获得疗效又较安全的剂量称为（）
A.极量
B.常用量
C.半数有效量
D.最小有效量
答案
参考答案：B
搜题请搜索小程序“爱下问搜题”
临床上用于防治疾病中即获得疗效又较安全的剂量称为（）
A.极量
B.常用量
C.半数有效量
D.最小有效量
参考答案：B
| 阅读理解。 | ||||
| Children in England mustn't work until they are 13. They need to have a work permit (许可) to start working.
| ||||
| 1.In England how old do children have to be before they can work? | ||||
[ ] | ||||
| A.15 B.14 C.10 D.13 | ||||
| 2.Paperboys and Papergirls deliver newspapers ______. | ||||
[ ] | ||||
| A.early in the morning B.at noon C.in the afternoon D.in the evening | ||||
| 3.Teenagers in England can do all of the following except ______. | ||||
[ ] | ||||
| A.work in an office B.work in a night club C.look after young children D.deliver newspapers | ||||
| 4.How many hours a week many teenagers work during the term time? | ||||
[ ] | ||||
| A.10 B.14 C.17 D.20 |