生物 1994 年 DSE、CE 選擇題（第 6 頁）

51.

The diagram below indicates the relative number of organisms at three different trophic levels in a food chain:

Which food chain can be represented by the above diagram?

52.

The following graph shows the changes in the numbers of two species of organisms in the same habitat over a period of time:

The probable relationship between species A and species B is

53.

A continuous supply of energy is essential for the maintenance of a stable ecosystem because

54.

Directions: Questions 55 and 56 refer to the diagram below which shows a simplified nitrogen cycle:

Which of the following processes does NOT involve the action of microorganisms?

55.

Directions: Questions 55 and 56 refer to the diagram below which shows a simplified nitrogen cycle:

Which of the following processes would be promoted by growing soya bean?

56.

Vegetables can be stored for a longer period at around 4°C because at this temperature

(1)the activities of microorganisms are slowed down.

(2)the enzymes in the food are inactivated.

(3)the evaporation of water in the food is reduced.

57.

Many countries do not allow the use of DDT as an insecticide because

58.

Which of the following statements about air pollution is incorrect?

59.

Red tides are probably caused by