问题 问答题 简答题

计算题:某干熄焦提升机变压器电压为3000V,提升机卷上、卷下电动机的功率为160kW、电压为380V、功率因子cosθ为0.9。试计算该干熄焦提升机的额定电流。

答案

参考答案:

I=P/(1.732×U×cosθ)=160/(380×1.732×0.9)×1000=270A。

阅读理解

Heart disease is the most common cause of death in the United States. Over a million people each year will have a heart attack and 25% will die before they get to the hospital or in the Emergency Department. _1_  Prevention is the best way so it does not damage your heart and limit your ability to enjoy life. Simple ways might help reduce your risk:

Don’t smoke

This means that you should stop smoking as soon as possible if you already smoke, and if you live with a smoker , you should put limits on the smoker.  _2_  

Get moving

__3_  Find a form of exercise you enjoy enough to want to do it regularly and stick to it. If you have health issues that limit exercise, see your doctor for suggestions and make sure you begin with a program that will not be too challenging for you to keep with it.

__4__

Make sure you follow a heart prevention diet, even if you don’t have any symptoms (症状) of heart disease.  _5_  You should eat a high-fiber, low-fat diet rich in fruits, vegetables and whole grains. Meats should be lean (瘦的),and fats should be limited to heart healthy fats such as olive oil. Sugars and processed foods should be limited, and fruits and vegetables should make up a large part of your daily meals.

A.Eat healthy foods

B.Manage your weight

C.A heart attack is a very frightening event.

D.The key is to prevent the disease before it startsE. It’s best if you can get in 30 minutes a day of exercise.

F. If you feel any of these heart attack symptoms, do not ignore.

G. If you haven’t started smoking, be sure never to start this habit.

填空题