Điền từ còn thiếu vào ô trống
Most of the world's surface is water. We may know the.............very well, but we know very...............about the oceans.
Until recently, man could not stay underwater for long. A pearl diver,.................example, could not stay underwater for longer.................two minutes. But now, with speacial..................equipment, a diver can stay underwater for a long time. After the invention of this equipment, man could.................freely underwater and scuba-diving became a popular...................
Điền từ còn thiếu vào ô trống
Most of the world's surface is water. We may know the......land.......very well, but we know very.........little......about the oceans.
Until recently, man could not stay underwater for long. A pearl diver,........for.........example, could not stay underwater for longer..........than.......two minutes. But now, with speacial.........breathing.........equipment, a diver can stay underwater for a long time. After the invention of this equipment, man could..........swim.......freely underwater and scuba-diving became a popular.........sport..........
