Which of the following does not pollute the air?

A. 4
B. 8
C. 17
D. 18

A. Magnetic tape
B. Modulator
C. Sonometer
D. Reed instrument

A. methane
B. ethane
C. hydrogen
D. butane

In human body there are_________________kinds of bones?

A. 3
B. 4
C. 5
D. 6

TYPES OF BONES:

Bones of the skeleton can be grouped into the following major types: long, short, flat, and irregular. Each type has a somewhat different construction pattern.

1. Long Bones: The basic structure of a long bone is illustrated in figure 4-1. Example: femur.
2. Short Bones: The short bones, such as those of the wrist and feet, have a thin layer of compact bone surrounding an inner mass of spongy bone. Example: carpal bones.
3. Flat Bones: The flat bones are constructed with two plates of compact bone, which enclose between them a layer of spongy bone. The spongy bone is richly supplied with blood vessels and red marrow. Example: the cranial frontal bone.
4. Irregular Bones: The irregular bones are those that do not fit into the three categories above. Example: a vertebra.

A. vitamin C
B. vitamin D
C. vitamin A
D. vitamin E

A. Brain
B. Spinal cord
C. Larynx
D. Eye