某种细菌在培养过程中,每20分钟分裂一次(一个分裂为两个).经过3个小时,这种细

题型:选择题

问题:

某种细菌在培养过程中,每20分钟分裂一次(一个分裂为两个).经过3个小时,这种细菌由1个可繁殖成(  )
A.511个B.512个C.1023个D.1024个
考点:指数与指数幂的运算(整数、有理、无理)
题型:选择题

位于颏唇沟的正中凹陷处的是()。

A.水道

B.迎香

C.廉泉

D.承浆

E.水沟

题型:选择题

一定质量的理想气体从状态A开始变化到状态B。如图所示,已知状态A的

温度为400K。则变化到B状态时气体的温度为_____K,AB过程中最高温度_____K

(保留三位有效数字)。

题型:选择题

Stress is with us all the time. It comes from mental or emotional activity as well as physical activity. It is unique and personal to each of us. So personal, in fact, that what may be relaxing to one person may be stressful to another. For example, if you’’re a busy executive who likes to keep occupied all of the time, "taking it easy" at the beach on a beautiful day may be extremely frustrating, nonproductive, and upsetting. You may be emotionally distressed from "doing nothing." Too much emotional stress can cause physical illnesses such as high blood pressure, ulcers, or even heart disease. Physical stress from work or exercise is not likely to cause such ailments. The truth is that physical exercise can help you to relax and to better handle your mental or emotional stress.

One method mentioned to help handle stress is________.

A.physical exercise

B.tranquilizers

C.drugs

D.taking it easy

题型:选择题

盘、柜在安装固定好以前,应有()的措施,特别是重心偏在一侧的盘柜。

A.防碰撞

B.防坠落

C.防止倾倒

D.防盗

题型:选择题

促进果树花芽分化应当适量喷施:()

A、磷酸二氢钾

B、乙烯利

C、秋水仙素

D、淡盐水

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