1) The Straits of Gibraltar are 20 km ............ .

a. wide         b. deep           c. long             d. high

2) There is no -------- of live on Mars.

a. texture       b. density        c. satellite        d. evidence

3) Veins are narrow tubes which have thin wall.They are---------

a. ductile         b. inelastic      c. pointed        d. circular

4) The --------- heart weighs about 300 gr.

a. muscular      b. bright          c. average       d. arterial

5) Sound waves enter the ear and produce -------- in the eardrum.

a. lubrications     b. composition     c. protection      d. vibrations

6) The troposphere extends from sea level to a(n) ------- of 10 miles.

a. altitude        b. height         c. region         d. both a&b

7) The -------,the outer atmosphere of the sun, is located above the chromosphere.

a. crust            b. corona       c. upper mantle      d. lower mantle

8) The control unit of a computer -------data and instructions from the memory unit .

a. subtracts       b. converts     c. interprets        d.selects

9) Some worker bees protect the --------- of the hive.

a. exess             b. entrance      c. mineral           d. device

10) The behavior of the workers shows considerable -------- of labor.

a. structure         b. division       c. production      d. interaction

11) A rocket has to follow a(n) -------- path.

a. sterile              b. exact           c. kinetic            d. central

12) The body cannot use all the materials in food. It must ------ waste.

a. digest              b. take in          c. eliminate         d. absorb

13) It is necessary for the body to ------- food throughout the body.

a. obtain              b. receive          c. alter              d. distribute

14) Computers can perform ------- complex calculations.

a. extremely         b. immediately     c. similarly       d. relatively

15) The ------ enables an airplane to ascend or descend.

a. elevator            b. propellor          c. altimeter      d. rudder

 16) A computer can ------- errors and correct them.

a. work out           b. perform           c. detect          d. communicate

17) Wood cannot dissolve in water.It is a(n) ------- substance.

a. invaluable          b. conductor        c. insoluble       d. compound

18) Bats ------- ultrasonic sounds which enable them to hear the echoes of these sounds.

a. locate                b. distant              c. send out        d. avoid

19) Some organisms have to change ------- suit their environment.

a. in order that        b. so that             c. that               d. in order that

20) The lungs of a man do not ------- in water.

a. utilize                  b. dissolve            c. obtain           d. function

 21) The birds" beaks are adapted ------- insects,fish or other food.

a. to catch               b. to catching        c. catch            d. catching

22) Water is necessary for life. --------- no living thing can exist without water.

a. In other words      b. On the other hand      c. Similarly       d. In addition

23) The fuel system provides petrol ------ the engine.

a. with                      b. for                    c. from              d. of

24) The ------ presents the information to the user.

a. memory unit          b. input device       c. output device       d. control unit

25) All insects are ------ three parts-head,thorax and abdomen.

a. made up                b. formed              c. consist of             d. composed of

26) Flowers ------- the plant"s reproductive organs.

a. protect                    b. grow                c. develop              d. contain

27) Most plants have the ------- organs in the same flower.

a. fat and round          b. single and compound         c. male and female     d. top and bottom

28) The battery has two terminals. The bulb -------- the positive terminal.

a. enclosed in             b. rests on             c. is attached           d. runs through