(1)
A)They are accurate and easy to pull.
B)Their shooting range is 40 yards.
C)They are usually used indoors.
D)They took 100 years to develop. (2)
A)It went out of use 300 years ago.
B)It was invented after the shortbow
C)It was discovered before fire and the wheel.
D)It's still in use today. (3)
A)Because it was too heavy.
B)Because it did not bend easily.
C)Because it did not shoot far.
D)Because its string was short.
原文：
Bows and arrows, are one of man's oldest weapons. They gave early man an eff ective weapon to kill his enemies. The ordinary bow or short bow as used by near ly all early people. This bow had limited power and short range. However, man ov ercame these faults by learning to track his targets at a close rane. The long h ow was most likely discovered when someone found out that a five-foot piece of w ood made a better bow than a three-food piece. Hundreds of thousands of these bo ws were made and used for three hundred years. However, not one is known to surv ive today. We believe that a force of about one hundred pounds was needed to pul l the string all the way back on a long bow. For a long time the bow was just a bent stick and string. In fact, more changes have taken plae in a bow in the past 25 years than in the last 7 centuries. Today, bow is forceful. It is as exact as a gun. In addition, it requires little strength to draw the string. Modern bo ws also have precise aiming devices. In indoor contest, perfect scores from 40 y ards are common. The invention of the bows itself ranks with discovery of fire a nd the wheel. It was a great-step-forward for man.
18. Why did man have no track his target at a close range when using a short bow ?
19. What does the passage tell us about long bow?
20. What do we know about modern bows?