（）负责对实施情况进行监督检查。 A.上级主管单位 B.领导班子 C.行政职能部门

简述杂物电梯与乘客电梯安全钳要求的差异。

除去下列杂质，所用试剂和方法不正确的是（　　）

A．KOH （ K₂CO₃）Ca（OH）₂溶液、过滤

B．KNO₃（K₂SO₄）  Ba（NO₃）₂溶液、过滤

C．H₂SO₄（HCl）    AgNO₃溶液、过滤

D．CuO （KNO₃）    水、过滤

把pH=3的H₂SO₄溶液和pH=10的NaOH溶液混合，两者恰好中和，则两种溶液的体积比是（　　）

A．10：1

B．1：100

C．1：10

D．1：2

阅读理解。

     Outside her shabby cottage, old Mrs. Tailor was hanging out laundry on a wire line, unaware that

some children lay hidden in the leaves of a nearby tree watching her every move. They were determined

to find out if she really was a witch.

     They watched as she took a broomstick to clean the dirt from her stone steps. But, much to their

disappointment, she did not mount the broomstick and take flight. Suddenly, the old lady's work was

interrupted by the cackling of her hen-a signal that an egg had been laid in the warm nest on top of the

haystack.

     The old broomstick was put aside as she hobbled off towards the haystack followed by Sooty, a

black cat she had rescued from a fox trap some time back. With only three legs, it was hard for Sooty

to keep up with the old lady. The cat provided proof-the children were sure that only a witch could

own a black cat with three legs.

     There, standing on a wooden box, was Mrs. Tailor, stretching out to gather her precious egg. Taking

the egg in one of her hands, she began to climb down when, without warning, the box broke and the

old lady fell.

     "We have to got and help her," whispered Amy.

     "What if it is a trick?" replied Ben.

     "Don't be silly, Ben. If she were a witch, she would have turned us into frogs already," reasoned

Meg. "Come on Amy, let's go." The girls climbed down the tree and ran all the way to the haystack.

     Approaching carefully, they could see a wound on the old lady's face. She had knocked her head

on a stone and her ankle was definitely broken. "Go and get Dad," Amy yelled to her brother. "Tell him

about the accident."

     The boys did not need another excuse to leave. They ran as fast as they could for help, hoping that

Mrs. Tailor would not wake and turn the girls into frogs.

1. Were the children hiding in the tree?

A. They wanted to watch Mrs. Tailor do her housework closely.

B. They were playing a hide-and-seek game.

C. They wanted to find out if the rumors about Mrs. Tailor were true.

D. They were pretending to be spies

2. Mrs. Tailor stopped sweeping when _____.

A. her front steps were clean

B. she noticed the children in the tree

C. she was ready to take a flight

D. she heard the hen cackling

3. Ben did not rush in help Mrs. Tailor because _____.

A. he thought that she could be necking them

B. he knew that they could not have been in the tree

C. he did not the old lady fall down

D. he was afraid of the three-legged cat

4. Which of these old sayings best suits the story's lesson for us?

A. Make hay while the sun shines.

B. Never judge a book by its cover.

C. People in glasshouses should not the stones.

D. A bird in the hands worth two in the bush.

下列物质属于炔烃的是（）。

A.C₂H₆

B.C₃H₆

C.C₂H₂