Question

Ever since man has gone down to the sea in ships, he has been puzzled and fascinated by the phenomenon called "fiery waters" or "the burning of the seas". At night, whole areas of the sea light up with an unusual glow. Strange as it may look, there is nothing supernatural about this light. It is caused by simple one-celled organisms. This production of light by living organisms is called bioluminescence(生物发光).

Most of these single-celled forms make light whenever they are irritated by something around them. Some kinds, however, produce light only at night.

There are about forty main kinds of organisms that produce bioluminescence. Of all these, the fireflies, or lightning bugs, are the best known. Fireflies can control the blinking of their lights so that they serve as signals between males and females. Other insects, such as the cucujo beetle and the lantern fly found in tropical forests, produce a very intense light. An army surgeon once performed a successful operation under the light of a bottleful of cucujo beetles.

Another interesting luminescent animal is the water flea found in the seas of Orient. This small animal, which lives in the sand, comes out at night. As it moves about, it secretes(分泌) a luminous substance. The light that it produces is unusual in that it is blue. Most luminescent creatures produce a white or yellow light.

9. At night, the sea lights up because _________ .

A. a strange light lights up the sea

B. two-celled organisms can produce light

C. there's a phenomenon of "fiery waters"

D. there's something supernatural about this light

10. Which of the following statements is TRUE according to the passage?

A. All the organisms can give light when they are irritated.

B. None of these organisms can produce light of itself.

C. Most of these single-celled forms produce light whenever they are irritated.

D. All the organisms can make light both in the daytime and at night.

Answer 1

AC