Read the following passage and answer the questions that follow.
Passage:
Life on our planet earth began with earth. The earth is the only planet of our solar system so far known which contains plenty of water and this water has made a vast variety. Sea has given food and shelter to countless creatures. It is a potential source of protein. Sea, if used scientificall demands. Plankton or algae mostly constitutes the plant life. Like plant plankton there are also animal plankton; the smallest plankton feed on plant plankton and small fish. Thus, there is an unbroken chain of life in the sea. Arctic and Antarctic seas a also. Blue whales, the largest living creatures of the world, are also found here in great number. Some countries have develo that sea plants contain rich nutrients not found in other vegetarian food. Sea is not to be over exploited. Man in his greed has creatures so recklessly that some of their species have either become extinct or are on the verge of extinction. Now it is decic should be big enough to let baby fish escape through. Otherwise, killing of large quantities of very young fish would have an ,