新航路开辟后，人类历史发生了重大的转折。这一“转折”主要是指（） A.使欧洲的商路和

Jack is a twenty-year-old young man. Two years ago, when he finished middle school, he found work in a shop. Usually he works until ten o'clock in the evening. He is very tired when he gets home. After a quick supper he goes to bed and soon falls asleep. His grandma who lives downstairs is satisfied with (满意) him.

One day, on his way home, he met Mary. They were both happy. He asked the girl to his house, she agreed happily. He bought some fruit and drinks for her. And they talked about their school, teachers, classmates and their future . They talked for a long time.

“Have a look at your watch, please,” said the girl. “What time is it now?”

　　“Sorry, something is wrong with my watch,” said Jack. “Where's yours?”

　　“I left it at home.”

　　Jack thought for a moment and found a way. He began to stamp his foot on the floor, “Bang! Bang! Bang!”

　　The sound woke his grandma up. The old woman shouted downstairs, “It's twelve o'clock in the night, Jack. Why are you still jumping upstairs?”

小题1:Jack was ________ when he finished middle school.

A．sixteen　

B．eighteen　

C．twenty　

D．fifteen小题2:The old woman is satisfied with Jack because ________.

A．he's her grandson　　

B．he's clever

C．he can keep quiet　　

D．he gets home on time小题3:From the story, we can know that Mary is Jack's ________.

A．classmate　　

B．colleague (同事)

C．aunt　　

D．wife小题4:The word “stamp” in the story means ______ in Chinese.

A．盖印　　

B．跺　　

C．贴邮票　　

D．承认小题5:Jack stamped his foot on the floor in order (为了) ________.

A．to wake his grandma up

B．to make his grandma angry

C．that his grandma was going to tell him the time

D．that his grandma was going to buy him a watch

栓塞综合征

对婴幼儿心理健康的发展至关重要的是（）

A.母乳喂养

B.适宜的信息刺激

C.动作与语言的发展

D.良好的行为习惯

E.母亲的爱抚

在“验证力的平行四边形定则”实验中，应进行的步骤是：

A．只用一个弹簧秤，通过细绳把橡皮条的结点拉到同样位置0，记下弹簧秤的读数和细线方向，按同样比例作出这个力F的图示

B．记下两个弹簧秤的读数以及结点的位置

C．作出F₁和F₂的合力F，比较F和F

D．通过细绳用两个弹簧秤互成角度拉橡皮条，橡皮条伸长，使结点到达某一位置E．在桌上平放一块方木块，在方木板上垫一张白纸，把橡皮条的一端固定在板上的A点，用两根细绳结在橡皮条的另一端

F．描下两条细绳的方向，在纸上按比例作出两个力F₁和F₂的图示。

（1）将上述各步骤，按合理操作顺序列出           (用字母代)

（2）在实验中,作出如图所示的图，其中P为橡皮条的固定点，O为橡皮条与线的结点，用F₁和F₂两个力或用一个力拉橡皮条的结点都要到达O点，这是为了           ，这体现了           的物理思想。

操作调度绞车前应做（）检查。

A、检查绞车固定和二次保护是否可靠

B、不检查电气设备是否失爆

C、不检查绞车闸是否完好