问题 填空题

在研究滑动摩擦力时,是用弹簧测力计拉着木块在水平桌面上做 ______运动,弹簧测力计的示数表示 ______力的大小.根据 ______的条件可知,这时弹簧测力计的示数与 ______的大小相等,因此可间接地知道滑动摩擦力的大小.

答案

要研究摩擦力大小时,用测力计测出的是拉力大小,所以只有拉着物体做匀速直线运动时,拉力的大小才会等于摩擦力.

故答案为:匀速直线;拉;二力平衡;摩擦力.

阅读理解

Sushi is a kind of food made with a mixture of cooked or raw fish, vegetables, and rice. Although Sushi is most commonly considered to have its origin in Japan, it actually began in China during the 7th Century.

At that time, any fish caught had to be preserved. Raw fish was cleaned and then pressed between layers of heavy salt. After a couple of months, the whole process was complete. Over time, a discovery was made that by rolling the fish in rice that had been soaked in vinegar the fish was easily fermented (发酵) in a few days rather than months. The rice was then thrown away and the fish was eaten. However, with a food shortage, people began consuming the rice as well as the fish and thus, Sushi today as we know was born. However, in the 1800s, a famous chef by the name of Yohei created two styles of Sushi—one called Edo, and the second, Osaka, for two cities.

Sushi is usually consumed with hot green tea. Also, Gari is offered free and eaten between bites to create a better taste. Two kinds of sauce are usually available: one is soy sauce, which is poured on most kinds of Sushi; the other is a thick sweet sauce used on eel (鳗鱼).

Sushi has taken the world by storm and today is a multi-billion dollar industry. Its popularity continues to rise because people are looking for healthy food that is quick and easy to make. With such unbelievable popularity as well as the health benefits of eating Sushi, it is likely that this food will continue to be a part of everyday life for many more centuries to come.

小题1:Two kinds of Sushi, Edo and Osaka, were probably named after _______.

A.the chef’s name

B.their birthplaces

C.the name of fish

D.some kinds of food小题2:When people eat Sushi, Gari is used to _______.

A.keep Sushi last long

B.make green tea better

C.digest Sushi more quickly

D.make Sushi more delicious小题3:Why do people like Sushi today?

A.It is cheap and delicious.

B.It is served with free Gari.

C.It is beneficial to people’s health.

D.It is easy to be kept for a long time.小题4:What can be the best title for the text?

A.Delicious Sushi and Its Origin

B.How to Make Delicious Sushi

C.Yohei and Two Styles of Sushi

D.The Birthplace of Sushi—China

问答题 简答题