已知R1=2Ω，R2=6Ω，将它们串连接到电压为12V的电路中，则I1：I2=

阅读理解。

     We drink tea every day. But more than three hundred years ago most of the people in Europe

(欧洲) did not know anything about tea. Some people heard about it, but very few of them know what

to do with it. 

     There is a story about an English sailor (水手) who went to countries in the east,the west and the

south. He went to India and China. One day he came home and brought some tea as a present for his

mother. She told her friends about the present and asked them to a "tea party". When her friends came

to the "tea party", the old woman offered (给) them brown tea-leaves (茶叶). The old woman's friends

began to eat them. Of course, nobody liked the tea-leaves.

     At that time the sailor came in. He looked at the table and said, "Mother, what have you done with

the tea?"

     "I boiled (煮) it,as you said."

     "And what did you do with the water?"

     "I threw it away, of course." answered the old woman.

     "Now you may throw away the leaves, too." said her son.

1. Most of the people in Europe _____.

A. drank tea every day 300 years ago

B. drink tea every day

C. know nothing about tea

D. like to eat the tea-leaves

2. One day the English sailor brought his mother some tea from _____.

A. countries in the west

B. countries in the south

C. India or China

D. a tea shop in England

3. The sailor's mother asked her friends to her house, because _____.

A. the sailor told her to 

B. she wanted to ask her friends what to do with the tea

C. she liked to show off (炫耀) 

D. she wanted to sample (品尝) the tea together with her friends

4. At the "tea party", _____.

A. all the woman's friends spoke highly of the tea

B. nobody knew what to do with the tea

C. the woman offered her friends some dried (干的) tea

D. the woman gave her friends each a glass of tea water

5. What mistake did the old woman make? She _____.

A. boiled the tea

B. did as the sailor said 

C. poured away the water

D. didn't throw away the tea-leaves

选择所缺的字母或字母组合，把序号写在括号里。

( ) 1. h__ppy ( ) 2. __ __m   ( ) 3. h__ __d  ( ) 4. h__ __r ( ) 5. sh__ __t ( ) 6. bl__ __d A. m  A. er A. an A. an A. au A. ae     B. a  B. oo B. am B. ai B. or B. ou     C. o C. ar C. ae C. ei C. ue C. oa    D. e D. ou D. au D. ao D. ai D. on

某同学为判断A、B、C三种金属的活动性顺序，设计了下列两个实验：

①将金属A放入B  的盐溶液中，看能否置换出B；

②将金属B放入C的盐溶液中，看能否置换出C．

当通过①、②中的现象仍无法判断出三种金属的活动性顺序时，还需要补做的一个实验是（　　）

A．将金属C放入A的盐溶液中，看能否置换出A

B．将金属B放入酸溶液中，看能否置换出酸中的氢

C．将金属A放入酸溶液中，看能否置换出酸中的氢

D．将金属C放入酸溶液中，看能否置换出酸中的氢

光在空气中的传播速度为3×10⁸m/s，光在水中的传播速度为空气中的

3

4

，求光在空气中传播3m所需的时间内在水中能传播多远？

下列关于周期表中元素分界线的叙述中正确的是（　　）

A．通常用来制农药的元素，在分界线附近

B．制半导体材料的元素，位于分界线的左下方

C．分界线两侧的元素中，可用作催化剂或制耐高温材料

D．周期表中分界线，把表中元素分成金属和非金属两个区域