某射手进行射击训练,假设每次射击击中目标的概率为35,且各次射击的结果互不影响.

题型:解答题

问题:

某射手进行射击训练,假设每次射击击中目标的概率为
3
5
,且各次射击的结果互不影响.
(1)求射手在3次射击中,至少有两次连续击中目标的概率(用数字作答);
(2)求射手第3次击中目标时,恰好射击了4次的概率(用数字作答);
考点:概率的基本性质(互斥事件、对立事件)n次独立重复试验
题型:解答题

初产妇潜伏期延长是指从临产规律宫缩开始至宫口开大3cm超过多少小时()。

A.12小时

B.14小时

C.10小时

D.16小时

E.18小时

题型:解答题

下列不是重症胰腺炎体征的是()

A.上腹或全腹压痛明显

B.肠鸣音增加

C.Grey-Turner征

D.Cullen征

E.腹肌紧张、反跳痛明显

题型:解答题

张某家被盗3000元案,下列属于破案的条件是()。

A、犯罪事实已有证据证明;

B、有证据证明犯罪事实是犯罪嫌疑人实施的;

C、经过县级以上公安机关负责人批准;

D、犯罪嫌疑人或者主要犯罪嫌疑人已经归案。

题型:解答题

艾滋病病毒感染人体后主要损害的靶细胞是

A.CD8+T淋巴细胞
B.CD4+T淋巴细胞
C.嗜中性粒细胞
D.嗜酸性粒细胞
E.巨噬细胞

题型:解答题

Spiders of many species change color to match the pigmentation of the flowers they sit on. The insects preyed on by those spiders, unlike human beings, possess color discrimination so acute that they can readily see the spiders despite the seeming camouflage. Clearly, then, it must be in evading their own predators that the spiders’ color changes are useful to them.
Which of the following, if tree, most strengthens the argument

A.Among the animals that feed on color-changing spiders are a few species of bat, which find their prey through sound echoes.

B.Certain animals that feed on color-changing spiders do so only sparingly in order to keep from ingesting harmful amounts of spider venom.

C.Color-changing spiders possess color discrimination that is more acute than that of spiders that lack the ability to change color.

D.Color-changing spiders spin webs that are readily seen by the predators of those spiders.

E.(E) The color discrimination of certain birds that feed on color-changing spiders is no more acute than that of human beings.

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