问题 选择题

下列各现象中,不能用光的直线传播规律解释的是(  )

A.人在太阳光下,地面上会形成影子

B.射击时,用“三点一线”的方法来瞄准

C.日食和月食的形成

D.人能看见本身并不发光的物体

答案

A、人在太阳光下,地面上会形成影子,是光的直线传播形成的,不符合题意;

B、射击时,用“三点一线”的方法来瞄准,利用了光的直线传播,不符合题意;

C、日食和月食的形成,是光的直线传播形成的,不符合题意;

D、人能看见本身并不发光的物体,是由于物体反射的光进入人的眼睛里,属于光的反射现象,符合题意.

故选D.

单项选择题 B型题
阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项.选项中有两项为多余选项.

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time with others. Ask your family members, friends or co-workers for help.

☆Don't overdo it, especially at first. You can slowly increase the time and intensity (强度) of your

activities as you become more fit.    5  

☆Keep a record of your activities. Reward yourself at times. Nothing will inspire you more than success!

A.Try to make it a habit, but be flexible.

B.They all cause you to feel warm and breathe heavily without being out of breath.

C.Be an active role model for your children.

D.That way, exercise will never seem boring.

E.If you are overweight or have a high risk of heart disease, see your doctor for medical advice before

exercising.

F.Surround yourself with supportive people.

G.Gradually, work up to exercising on most days of the week for 30-60 minutes.