The journey two divers(潜水员)made some time ago to the very deepest point on the earth make us realize how much of the world still remains to be studied. The two men went down seven miles to the bottom of the Pacific Ocean inside a small ball to find out if there are any ocean currents(水流)or signs of life.
A.
if there are water currents and life in the great depths
B.
if people can stand the severe cold in the great depths