搜题请搜索小程序“爱下问搜题”
问题 选择题
已知θ为锐角，则下列选项提供的各值中，可能为sinθ+cosθ的值的是（　　）
A．
4
3
B．
3
5
C．
4
5
D．
1
2
答案

由题意得，sin θ+cos θ=

2
sin(θ+
π
4
)，

∵θ为锐角，∴

π
4
＜θ+
π
4
＜
3π
4
，

则

2
2
＜sin(θ+
π
4
)≤1，即1＜
2
sin(θ+
π
4
)≤
2
，

故选A．

单项选择题

Extraordinarily few people have the ability to be successful commodity traders. So rather than limit the number of people they hire, trading firms aim to hire all those applicants who are able to be successful and to reject the rest. By this standard Quinsey-Leerheim’s record is perfect. All of its entry-level hirees over the past decade have become successful commodity traders.
Which of the following, if true, would cast the most doubt on the assessment given above of Quinsey-Leerheim’s hiring performance

A．Over the past decade, Quinsey-Leerheim’s trading practices and policies have changed in a way that gives much more responsibility to individual traders.

B．Since the pool of entry-level applicants is mostly the same for all commodity-trading firms, Quinsey-Leerheim often competes with other trading firms for the pest applicants.

C．Quinsey-Leerheim rejects some entry-level applicants who go on to become extremely successful commodity traders with other trading firms.

D．Commodity trading requires skills that are needed in very few other occupations, so that trading firms’ hiring procedures typically differ significantly from those of other financial firms.

E．(E) Commodity trading is very stressful, and even successful commodity traders rarely work as traders for longer than ten years, although they often earn substantial sums in those years.
查看答案
单项选择题

患女48岁，已婚。月经紊乱1年，停经40天后突然 * * 大量出血3天，经色深红、质稠，口渴烦热，小便黄，大便干结，舌红苔黄，脉洪数。妇科检查未见异常，子宫内膜为腺囊型增生过长。应首先考虑的是

A．无排卵型DUB虚热证
B．无排卵型DUB实热证
C．无排卵型DUB血瘀证
D．排卵型月经过多虚热证
E．排卵型月经过多血瘀证
查看答案