问题 实验题

小梓用U形管压强计去探究液体内部压强的规律。

(1)小梓选压强计和一大烧杯的水进行了三次实验如图甲所示。他探究的问题是:____________________________,实验过程中要判断探头承受液体压强的大小,主要是观察___________________________________。

(2)小梓探究“液体内部压强与液体密度的关系”时,选了另一种密度不同的液体做了如图乙所示的对比实验。由本实验可知,ρ___________ρ。(选填“>”、“<”或“=”)

答案

(1)液体内部压强与深度的关系  U形管的液面高度差 (2)<

由甲图知,容器所盛液体密度相同(都是水),金属盒所处深度不同.所以是探究液体压强与深度的关系;压强计中U形管内液面的高度差反映了液体内部压强的大小;由乙图可知,U形管的液面高度差相同,右边的深度少,所以ρ的密度大。

阅读理解

Popular breakfast foods in the United States, as in many other countries around the world, include coffee, milk , juice, eggs, and bread. Some other breakfast items served in the United States are thought by many to be traditionally American. However, they actually come from other cultures.

A very popular breakfast food in America is the pancake--- a thin , flat cake made out of flour and often served with maple syrup. The idea of the pancake is very old. In fact, pancakes were made long ago in ancient China.

Bagels, a round thick bread with a hole in the middle , are also popular for breakfast in America. Polish people in the late 1600s came up with the idea for the first bagels and this new kind of bread soon took off across Eastern Europe.

In the late 1800s, thousands of Jews from Eastern Europe travelled to the United States and brought the recipe for bagels with them. Today, New York bagels are said to be the best in the world. Many people have them with cream for breakfast on the go.

Doughnuts (usually spelled “donut” in the United States) came from France. They were served to American soldiers in France in the World War Ⅰ. After the war, American soldiers asked cooks in the United States to make doughnuts for them. Now , served with coffee, they are a very popular breakfast food across the United States.

小题1:This reading is mainly about ________

A.famous places to eat breakfast.

B.why people in the United States eat breakfast

C.the most popular types of pancakes in the United States

D.the history of popular breakfast foods in the United States.小题2:The oldest breakfast food in the passage is ______

A.the pancake

B.the bagel

C.the doughnut

D.The passage doesn’t say.小题3:Which sentence is true for both bagels and donuts?

A.They both came from Europe

B.They are both easy to make

C.They are both sweet

D.people in New York make them best小题4:Who brought bagels to America?

A.Polish people

B.Jewish People

C.Chinese People

D.American soldiers小题5:Who served donuts to American soldiers during World War Ⅰ?

A.French people

B.Jewish people

C.other American soldiers

D.cooks from the United States.

单项选择题