在横线里填上适当的数使计算简便513÷______+813×1499×45+__

题型:解答题

问题:

在横线里填上适当的数使计算简便
5
13
÷______+
8
13
×
1
4

99×
4
5
+______
考点:运算定律和简便算法
题型:解答题

对于Fe、Fe2+、Fe3+三种粒子的说法中不正确的是(  )

A.核电荷数相同

B.核外电子数相同

C.相对原子质量相同

D.属于同种元素

题型:解答题

1825年,英国解除机器出口的禁令。此举对当时世界产生的最主要影响是

A 有利于扩大英国的对外贸易

B 促使了工业革命在欧洲大陆和美洲的进一步扩展

C 使得英国很快被其它国家赶上并超过

D 促进英国自由资本主义的发展

题型:解答题

氯化铬酰(CrO2Cl2)在有机合成中可作氧化剂或氯化剂,能与许多有机物反应。请回答下列问题:

⑴写出基态铬原子的外围轨道表示式_______________________________,与铬同周期的所有元素的基态原子中最外层电子数与铬原子相同的元素有____________(填元素符号),其中一种金属的晶胞结构如右图所示,该晶胞中含有金属原子的数目为________。

⑵CrO2Cl2常温下为深红色液体,能与CCl4、CS2等互溶,据此可判断CrO2Cl2是__________(填“极性”或“非极性”)分子。

⑶在①苯、②C2H4、③CCl4、④CO2五种有机溶剂中,碳原子采取sp2杂化的分子有___________(填序号),CO2分子的空间构型是______________。

题型:解答题

For many people,  there is only one good reason to go to an amusement park: the roller coaster. But why do People go on roller coasters?

"Where else in the world can you scream at the top of your lungs and throw your arms in the air?"  Frank Farley asks. "If you did that in most other places, they'd take you to your parents and probably put you through a psychological evaluation  (心理检查)."  Farley is a psychologist at Temple University in Philadelphia, Pennsylvania.

Roller coasters are often attractive to kids whose lives are stressful or controlled.  "Roller coasters are a way of breaking out of the humdrum (单调 ) of everyday life.  You can let it all go and scream and shout or do whatever you want," Farley says. It has been proved that many adults feel the same way.

Compared with skateboarding, extreme mountain biking, and other adventure sports, riding roller coasters is safe. Parents usually don't mind when kids go on coasters.  Roller coasters also have a way of bringing people together.  Riders share the thrill and adventure of surviving what feels like an extreme experience.

Whether you like to ride a roller coaster may depend on your personality.  Psychologists say that there is a certain type of person that naturally seeks out extreme experiences. "They enjoy things like change, variety, and intensity (强度)," says Farley. "These people are actually attracted to thrills."  He describes such people as having Type-T personalities ("T" stands for thrill).

He also believes that these thrill seekers are more adventurous and creative than other people. Albert Einstein was a Type T. "If nobody liked to seek stimulation (刺激)," he argues, "the human race wouldn't be where it is today."

1. What is the passage mainly about?

A. The disadvantages of roller coasters.

B. The characteristics of roller coasters.

C. Why many people enjoy roller coasters.

D. How people act when riding roller coasters.

2. According to Farley, what will most people feel after riding a roller coaster?

A. Scared.          B. Confident.    C. Nervous.       D. Relaxed.

3. If a person is a Type T, he seems to           .

A. enjoy adventure sports

B. dislike riding roller coasters

C. like popular sports

D. work well with others

4. According to Farley, to our society, people with Type-T personalities are __

A. dangerous            B. important    C. useless               D. harmful

题型:解答题

在腹部,前正中线旁开0.5寸的经脉是:()

A.足太阳膀胱经

B.足少阴肾经

C.足阳明胃经

D.足太阴脾经

E.足厥阴肝经

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