静止液体内任一点的液体静压力在各个方向上都相等。

下列化合物哪个不是胆色素

A．胆绿素

B．血红素

C．胆红素

D．胆素原

E．胆囊

提高电感式传感器线性度有哪些有效的方法。

A punctual person is in the habit of doing a thing at the proper time and is never late in keeping an appointment.

The unpunctual man, on the other hand, never does what he has to do at the proper time. He is always in a hurry and in the end loses both time and his good name. A lost thing may be found again, but lost time can never be regained. Time is more valuable than material things. In fact, time is life itself. The unpunctual man is for ever wasting and mismanaging his most valuable asset as well as others’. The unpunctual person is always complaining that he finds no time to answer letters, or return calls or keep appointments promptly. But the man who really has a great deal to do is very careful of his time and seldom complains of want of it. He knows that he can not get through huge amount of work unless he faithfully keeps every piece of work when it has to be attended to.

Failure to be punctual in keeping one’s appointments is a sign of disrespect towards others. If a person is invited to dinner and arrives later than the appointed time, he keeps all the other guests waiting for him. Usually this will be regarded as a great disrespect to the host and all other guests present.

Unpunctuality, moreover, is very harmful when it comes to doing one’s duty, whether public or private. Imagine how it would be if those who are put in charge of important tasks failed to be at their proper place at the appointed time. A man who is known to be habitually unpunctual is never trusted by his friends or fellow men. 

12. What is an unpunctual person like?

A. He always does a thing when it should be done.  B. He is always very busy.

C. He always does a thing at the wrong time.    D. He always keeps the appointments.

13. Why is unpunctuality very harmful?  

A. Because it makes a man lose many chances of doing important affairs.

B. Because it makes a man lose friends.

C. Because it makes a man work quickly.

D. Because it makes a man be more respected by others.

14. According to the passage, which is right?

A. The punctual person has no much work to do.

B. The unpunctual person is very rich

C. The unpunctual person is often respected by his friends.

D. The unpunctual person loses what can’t be regained again.

15. According to the passage, what are good manners when you are invited to a party?

A. Arriving at the appointed time.   B. Arriving before all other guests.

C. Arriving after all other guests.    D. Keeping all other guests waiting.

16. Why is a person always unpunctual?

A. He is too busy.                     B. He has too much work to do.

C. He does care much about time.         D. He doesn’t manage his time properly.

已知：①A、B、C、D四种物质均含有元素X，可能还含有元素Y或Z．元素Y、X、Z的原子序数依次递增且不超过20．②X在A、B、C、D中的化合价分别为0、-1、+1、+5．③室温下单质A与某种常见一元强碱溶液反应，可得到B和C．④化合物D在二氧化锰催化下受热分解，可制得元素Y的单质．请回答下列问题：

（1）写出元素X、Y、Z的元素符号：X：______，Y：______，Z______．

（2）写出A、B、C、D的化学式：A______，B______，C______，D______．

（3）画出Y原子的结构示意图______；写出③中反应的化学方程式______．

（4）写出④中反应的化学方程式______．实验室通过反应④制得元素Y的单质后，如何将产物分离并分别获得纯净物？写出实验步骤：

（5）制得元素Y的单质，若收集到标准状况下6.72LY单质气体，至少需要多少克化合物D？同时生成氯化物的物质的量为多少mol？（用涉及到的化学式写出计算步骤）

起于翼外板外面的肌肉为()

A．翼内肌

B．嚼肌

C．二腹肌后腹

D．颞肌

E．翼外肌