问题 问答题

体积为0.2m3的实心铁块浸没水中,求:铁块受到的浮力(g=10N/kg)

答案

∵铁块全部浸没在水中,

∴V=V=0.2m3

铁块受到的浮力:

FgV=1.0×103kg/m3×10N/kg×0.2m3=2000N.

答:铁块受到的浮力为2000N.

选择题
阅读理解

阅读理解。

     The western alphabet, which is used in Europe, the Americas, Africa, Australia and New Zealand as well

as in other countries, originated in the Middle East. The people who gave the world this alphabet were the

Phoneacians, a people who established colonies all over the Mediterranean, including Carthage in Africa and

Gades in Spain. In their alphabet, the letters were represented by little pictures which represented sounds. The

Phoneacian A was aelph, which means"bull", and it was made from a little picture of a bull's head. The letter B

was beth which meant"house", and showed the round-roofed buildings which you can still see today in Syria.

     The Phoneacians had contact with another nation of sailors, the Greeks, with whom they fought and traded. The Greeks also started to use the Phoneacian alphabet. They changed the names, so aelph and beth became

alpha and beta. The shapes of the letters are the same, but they have been turned sideways. If you know any

Greek, you can try turning the letters around again, and see how they look. You will see that the curve on the

right of the Greek A becomes the horns of a little bull.

     Of course, the first two letters of the alphabet give it its name. Over the years there have been changes.

Latin developed an alphabet with some different letters to the Greeks, and other letters have been added since.

But really westerners are using the same system of writing which has served them so well for thousands of

years.

1. What is the purpose of this text?

A. To share something of the Phoneacian history.

B. To tell the story of the western alphabet.

C. To compare the western alphabet with others.

D. To describe the order of the Greek alphabet.

2. Where did the western alphabet originally come from?

A. Carthage.

B. Gades.

C. The Mediterranean.

D. The Middle East.

3. Which picture, according to the text, represents beth?

4. Which change did the Greeks make to the Phoneacian alphabet?

A. They changed the pictures to sounds.

B. They put a curve on the letter A.

C. They changed the shape of the letters.

D. They turned the letters in a different direction.

5. Which of the following shows the development of western alphabet?

① More letters were added to the alphabet.

② Little pictures represented sounds.

③ The letters were turned sideways.

④ The names of the letters were changed.

A. ②→④→③→①

B. ①→③→②→④

C. ③→①→④→②

D. ④→②→①→③