问题 填空题

某同学制作了一个结构如图(a)所示的温度计。一端封闭的轻质细管可绕封闭端O自由转动,管长0.5m。将一量程足够大的力传感器调零,细管的开口端通过细线挂于力传感器挂钩上,使细管保持水平、细线沿竖直方向。在气体温度为270K时,用一段水银将长度为0.3m的气柱封闭在管内。实验时改变气体温度,测得封闭气柱长度l和力传感器读数F之间的关系如图(b)所示(实验中大气压强不变)。

(1)管内水银柱长度为m,为保证水银不溢出,该温度计能测得的最高温度为()K。

(2)若气柱初始长度大于0.3m,该温度计能测量的最高温度将()(选填:“增大”,“不变”或“减小”)。

(3)若实验中大气压强略有升高,则用该温度计测出的温度将()(选填:“偏高”,“不变”或“偏低”)。

答案

参考答案:0.1;360;减小;偏低

阅读理解

阅读理解。

     Five million people visit Grand Canyon in the US every year. For the purpose of helping project Grand

Canyon for your fellow visitors and future generations, please follow the guidelines below. 

Camping 

     To project the park, camping is allowed only within permitted campgrounds. Permits are required for

overnight camping at the North Rim. Advance booking can be received by mail. Please write: Information

Center, P.O. Box 129, Grand Canyon, AZ 86023

Fires

     Because of the extreme fire danger, campfires are not allowed except at Mather and Desert View

campgrounds. Collection of firewood is not allowed either.

Hiking (远足)

     Please stay on permitted paths. Otherwise you may destroy desert plants. Pack out what you pack in,

so you leave no signs of your visit. It is important to keep in mind that you are in a national park where

wildlife exists.

Weather

     The weather at Grand Canyon can change very quickly. With so much rock, lightning (闪电) causes

a particular danger during sudden summer storms. These storms also frequently bring floods inside valleys,

a danger to hikers. Watch the skies and check daily weather reports.

Wildlife

     Do not feed park wildlife. There have been a few cases at Grand Canyon National Park where deer (鹿)

were purposely shot because they are plastic bags that left them sick and weak. Hungry deer can be danger

and have kicked and bitten visitors at Grand Canyon. Some other animals will also beg and bite. For your

own safety and the well-being of the animals, please do not feed wildlife, no matter how gentle they may

appear.

1. What can you do first if you want to go camping?

A. Know the permitted

B. Book campgrounds in advance

C. Make sure not to make a fire

D. Stop at Mather and Desert View

2. What do the underlined words "pack out what you pack in" in Paragraph 4 probably mean?

A. keep every out of campgrounds

B. take away everything you bring in

C. carry all the necessary food

D. look after your personal belongings

3. Why were some deer killed on purpose at Grand Canyon?

A. They ate wrong things and became very ill.

B. They were a danger to other gentle animals.

C. They begged food from visitors.

D. They kicked and bit visitors.

4. What is the main purpose of the text?

A. To provide travel information.

B. To report some recent news.

C. To teach tourists hiking skills.

D. To introduce the wild life.

单项选择题