阅读理解。 Before you use your new microwave

题目：

阅读理解。

         Before you use your new microwave oven, read the instructions carefully. Each oven has its own

control panel (控制板), but most microwave ovens operate in a similar way. Look at the control panel. It

shows the time at the top of the panel. Under the time are the different functions (功能).You can press

Defrost, Cook, Clock, or Power. You can also warm food by pressing Reheat Times.

         Under the functions are the numbers. These numbers are shown as on telephone, from zero through

nine. You can press the numbers to set the cooking time in seconds or minutes. Under the numbers are Start

and Clear. 

         A microwave oven will automaticall (自动) cook on HIGH (power level 10) unless you enter a lower

power level. Suppose you want to cook a serving of broccoli for two minutes and forty-five seconds on

MEDIUM (power level 5). First, press the numbers2,4and5 (two minutes, forty-five seconds).Then press

Power. Next, press the number 5.At last, press Start to begin cooking. If you make a mistake, press Clear.

This will clear the display and allow you to start oven again.

根据短文回答下列问题

1. What is the main idea of the passage?

2. What functions does a microwave oven have?

3. How would you cook green beans for two minutes and thirty seconds at power level 7?

4. What is the last function you press each time you set the controls?

5. What does "Clear" allow you to do when you press it?