坎儿井是一种古老的饮水工程,长期为( )的绿洲居民所利用: A.新疆 B.内蒙古

题型:选择题

问题:

坎儿井是一种古老的饮水工程,长期为( )的绿洲居民所利用:

A.新疆

B.内蒙古

C.西藏

D.青海

考点:新疆维吾尔自治区西部地区的自然环境西部地区的生态保护与旅游资源的开发河西走廊
题型:选择题

阅读理解。

     Sally and her brother Jim are traveling to Europe. They like to travel by train or by ferry because they can

see a lot of beautiful sights in different places and they usually travel at night. Now they are sitting in a train.

It's dark outside and others are sleeping. The window near their seats is open. Sally is looking out of the

window. She can see some thin clouds in the sky. The Moon behind the thin clouds is very beautiful and bright.

She enjoys the Moon very much and doesn't feel tired. Jim is sitting near her and sleeping. Tomorrow they will

take a ferry to Paris.

1. Sally and Jim are traveling ______.

A. by ferry

B. by train

C. by plane

D. by bike

2. Why do they like to travel by train or by ferry?

A. Because it's very cheap.

B. Because they can travel very fast.

C. Because they can enjoy the beautiful sights.

D. Because they can sleep in a train.

3. Sally can see ______ in the sky.

A. some clouds and birds

B. some clouds and the Moon

C. the Moon and a plane

D. some snow

4. Jim is ______.

A. looking out of the window

B. enjoying the Moon

C. sleeping

D. singing

5. Sally and Jim will reach ______ tomorrow.

A. Paris

B. London

C. Rome

D. Beijing

题型:选择题

振源A带动细绳上各点上下做简谐运动,t=0时刻绳上形成的波形如图所示。规定绳上质点向上运动的方向为z轴的正方向,则P点的振动图像是

[ ]

A.

B.

C.

D.

题型:选择题

中晚期妊娠超声检查常采用某些参数估算孕龄,以提高诊断准确性,下列正确的是:()。

①BPD;

②HC;

③AC;

④FL。

A.①④

B.①②④

C.①②③

D.①②③④

E.①③④

题型:选择题
电气化铁路的输电线常用图所示的方式悬挂在钢缆上.钢缆的A端固定在电杆上,B端连接在滑轮组上.滑轮组由a、b、c三个滑轮构成,配重P由多个混凝土圆盘悬挂在一起组成,配重的总重为G,若不计摩擦和滑轮的重量,则以下说法中正确的是(  )

A.a为动滑轮,B端钢缆受到滑轮组的拉力大小约为3G

B.a为动滑轮,B端钢缆受到滑轮组的拉力大小约为G

C.a、c为动滑轮,B端钢缆受到滑轮组的拉力大小约为3G

D.a、c为动滑轮,B端钢缆受到滑轮组的拉力大小约为G

题型:选择题

电动机传给压缩机曲轴的实际功率为()

A.有用功率

B.理论功率

C.轴功率

更多题库