Clark Mueller, age 13, of Jackson, Miss., for his question:

WHERE IS THE KHYBER PASS?

The Khyber Pass is the most important pass connecting Afghanistan and Pakistan. It winds northwest through the Safed Koh range near Peshawar, Pakistan, for about 30 miles to Kabul, Afghanistan, varying in width from 15 to 450 feet. It is controlled by Pakistan.

The mountains on either side of the Khyber Pass can be climbed only in a few places and the precipitous walls vary in height from about 1,404 to 3,500 feet.

For centuries the Khyber Pass was used by invaders to enter India. During the Afghan Wars the pass was the scene of numerous skirmishes between Anglo Indian soldiers and native Afghans.

Particularly well known is the battle of    1842, in which about 16,000 British and Indian troops were killed.

The British constructed a road through the pass in 1879 and converted it into a highway during the 1920s. A railroad was also built through the pass in the 1920s.