问题 选择题

以下所列的对应关系,正确的是(  )。

A.氮的元素符号——n

B.钙的元素符号——cA

C.SO3中硫元素的化合价——+6

D.碳的相对原子质量——12g

答案

答案:C

分析:元素符号的书写规则是,当用一个字母时,就大写,当两个字母表示时,前大后小.当解释某一物质中某一元素的化合价时,一定要写物质在先,之后在对应元素上方标明化合价,一定是正负号在前,数字在后.相对原子质量的单位为1,而不是g.

解:A、氮元素,由于就是一个字母表示的,所以就是大写的N.

B、钙元素符号是用两个字母表示的,所以是前大后小为Ca.

C、三氧化硫中硫元素的化合价为+6价,应该先写化学式,之后在硫元素上方标注数据,正号在前,数字6在后,为D、由于相对原子质量是单位为1的比值,所以碳的相对原子质量为12,而非12g.

故选C.

点评:元素符号的书写一定是单一字母是大写,字母组合是前大后小.解释物质中的元素的化合价时要写上对应物质的化学式,之后在对应元素上标明化合价.

简答题
阅读理解

阅读理解

     While small may be beautiful,  tall is just plain uncomfortable it seems,  particularly when it comes to

staying in hotels and eating in restaurants.

     The Tall Persons Club Great Britain(TPCGB),  which was formed six months ago to campaign

(发起运动)for the needs of the tall,  has turned its attention to hotels and restaurants.Beds that are too

small,  shower heads that are too low,  and restaurant tables with hardly any legroom all make life

difficult for those of above average height,  it says.

     But it is not just the extratall whose needs are not being met.The average height of the population has

been increasing yet the standard size of beds,  doorways,  and chairs has remained unchanged.

     "The bedding industry says a bed should be six inches larger than the person using it, so even a

kingsize bed at 6'66" (6 feet and 6 inches) is falling short for 25% of men,  while the standard 6'3" bed

caters for(满足需要)less than half of the male(男性)population, " said TPCGB president Phil

Heinricy,  "Sevenfoot beds would work fine."

     Similarly, restaurant tables can cause no end of problems. Small tables,  which mean the longlegged have to sit a foot or so away from them,  are enough to make tall customers go elsewhere.

     Some have already taken note,  however. At Queens Moat Houses' Caledonian Hotel in Edinburgh, 6'6" beds are now put in as standard after requests for longer beds from taller visitors,  particularly

Americans.

1. What is the purpose of the TPCGB campaign?

A. To provide better services.

B. To rebuild hotels and restaurants.

C. To draw public attention to the needs of the tall.

D. To attract more people to become its members.

2. Which of the following might be a bed of proper length according to Phil Heinricy?

A. 7'2".      

B. 7'.      

C. 6'6".  

D. 6'3".

3. What may happen to restaurants with small tables?

A. They may lose some customers.

B. They may start businesses elsewhere.

C. They have to find easy chairs to match the tables.

D. They have to provide enough space for the longlegged.

4. What change has already been made in a hotel in Edinburgh?

A. Tall people pay more for larger beds.

B. 6'6" beds have taken the place of 6'3" beds.

C. Special rooms are kept for Americans.

D. Guest rooms are standardized.