Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 33 to 42
Magnets
A solid object that has the power to attract iron and some metals is called a magnet. It does this through its magnetic field, a region of force surrounding it. The (33) _____ the magnet, the more intense is the field.
Objects that are attracted to the magnet feel a force (34) _____ as “magnetism” when they are inside the magnetic field. This magnetic force can pass (35) _____ some materials. Even a weak magnet will attract a pin to the other side of a (36) ______ of paper, for example.
Magnets come in (37) ______ shapes. A familiar one is the curved horseshoes magnet. There are also bar magnets in the form (38) _____ disc or a stubby cylinder. Every magnet has (39) ______ poles, called north and south, at opposite ends of it: at the two ends of a horseshoes magnet, for example, or on the two sides of a disc.
Powerful magnets can be (40) _______ by passing an electric current through wire coiled around a piece of iron. The (41) _____ is called and electromagnet. Magnets are (42) ______ in many household and everyday devices. They are also commonly used in industrial machinery, usually in the form of electromagnets.Question 39
A. many
B. several
C. two
D. one
Đáp án : C
“pole”:cực. Nam châm nào cũng có 2 cực: Bắc – Nam