202 Common Science 



Both of these effects are best secured on a dry day, because 

 on a damp day the water particles in the air will let the 

 electrons pass to them as fast as they are rubbed up to the 

 surface of the hair. 



Inference Exercise 

 Explain the following : 



291. If you shuffle your feet on a carpet in clear, cold weather 



and then touch a person's nose or ear, a slight spark 

 passes from your finger and stings him. 



292. If you stay out in the cold long, you get chilled through. 



293. The air and earth in a greenhouse are warmed by the sun 



through the glass even when it is cold outside and when 

 the glass itself remains cold. 



294. When you hold a blade of grass taut between your thumbs 



and blow on it, you get a noise. 



295. Shadows are usually black. 



296. Some women keep magnets with which to find lost needles. 



297. You can grasp objects much more firmly with pliers than 



with your fingers. 



298. If the glass in a mirror is uneven, the image of your face is 



unnatural. 



299. A sweater clings close to your body. 



300. Kitchens, bathrooms, and hospitals should have painted 



walls. 



