1. When a solid changes into a liquid, it is called__________.

　　A. vaporization* B. melting C. evaporation*

　　2. When a solid changes directly into a gas, it is called_______.

　　A. sublimation* B. evaporation

　　3. When a gas changes into a liquid, it is called_________.

　　A. solidification* B. melting C. condensation*

　　4. Matter in a solid state has________volume and_________shape.

　　A. no definite, no definite B. a definite, a definite C. a definite, no definite

　　5. How many states of matter are there?

　　A. two B. three C. five

　　Answers:1. B. 2. A. 3. C 4. C. 5. B