16．Man，a land animal．But he is also closely tied to the sea．Throughout history the sea has served the needs of man．The sea has provided man with food and a convenient way to travel to many parts of the world．Today，nearly two-thirds of the world's population live within 80kilometers of the sea coast．
In the modern technological world，the sea offers many resources to help mankind survive．Resources on land are beginning to be used up．The sea，however，still can be hoped to supply many of man's needs．
The list of riches of the sea yet to be developed by man's technology is big．Oil and gas explorations have been carried out for nearly 30years．Valuable amounts of minerals exist on the ocean floor ready to be mined．
Fish farming promises to be a good way to produce large quantities of food．The culture of fish and shellfish （貝類動(dòng)物） is an ancient skill practised in the past mainly by Oriental people，including people in China．
Besides oil and gas，the sea may offer new sources of energy．Experts believe that the warm temperature of the ocean can be used in a way similar to the steam in a steamship．Ocean currents and waves offer possible use as a source of energy．
Technology is enabling man to explore ever more deeply under the sea．The development of strong，new materials has made this possible．
The technology to harvest the sea continues to improve．Experts believe that by the year 2020the problems that prevent us from exploiting（開發(fā)） fully the food，minerals，and energy sources of the sea will be largely solved．
67．Valuable amounts of minerals areD．
A．in the ocean water B．in the warm ocean water
C．on the sea coast D．on the ocean floor
68．We can conclude from this passage thatB．
A．the sea resources have largely been used up
B．the sea，in the broad sense，has not yet been developed
C．the problems that prevent us from using the food，minerals，and energy sources of the sea have already been solved．
D．by the year 2020，the technology will be good enough to exploit all the sea resources
69．The underlined words"Oriental people"in the fourth paragraph probably meanA．
A．the people in Asia B．African people
C．European people D．American people
70．The best title for this passage isA．
A．Sea Harvest B．Sea Food
C．Technology for Exploiting the Sea D．Man and the Sea．
