() Litmus paper is used to test the acidity of solutions. ( ) Gases have to be kept in closed containers. ( ) Light is a stream of particles and waves. ( ) Ultrasound is heard by many humans. () Modern drugs do not help to control AIDS. ( ) The earth goes around the sun twice a year. ( ) Cloth is a kind of material. ( ) Making new animals is crossbreeding. ( ) The baby of the horse is called mare. ( ) "Recover" means "to get back to normal health". () "Scare" means "fear". ( ) An event that causes damage is disaster. ( ) Richter scale is used to measure the strength of winds. () "Efficient" means "very lazy". () "Tum down advice" means "refuse advice". ( ) A house builder is someone who builds boats. ( ) Fruits are grown in deserts. ( ) Loomi is a kind of dried lemon. ( ) To row is to move the boat by using sail. ( ) To drag something is to throw it away.