处方开具当日有效，特殊情况下可以延长有效期，但有效期最长不得_爱下问搜题

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问题单项选择题

处方开具当日有效，特殊情况下可以延长有效期，但有效期最长不得超过（）

A.2天

B.3天

C.5天

D.7天

E.10天

答案

参考答案：B

解答题

已知等差数列{a_n}前三项之和为－3，前三项积为8.

(1)求等差数列{a_n}的通项公式；

(2)若a₂，a₃，a₁成等比数列，求数列{|a_n|}的前n项和．

填空题

Column A

①language acquisition device (LAD)
②stimulus and response
③the discourse theory
④acquisition and learning
⑤the input hypothesis

Column B

a. The former refers to the subconscious process leading to the development of "competence"; the latter refers to conscious study and knowledge of grammatical rules.
b. A sort of mechanism or device which contains the capacity to acquire one’s first language.
c. It assumes that humans acquire language in only one way—by understanding messages, or by receiving "comprehensible input".
d. It believes there is little difference between the first language acquisition process and the process of second language acquisition—only through communication discourses.
e. The former serves to elicit behaviour; the latter is triggered by the former.