Reading Comprehension

Read the following passage. Then answer the questions:

Sometimes the meaning of glowing water is ominous. Off
the Pacific Coast of North America, it may mean that the sea is
filled with a minute plant that contains a poison of strange
and terrible virulence. About four days after this minute
plant comes to alter the coastal plankton, some of the fishes
and shellfish in the vicinity become toxic. This is because in
their normal feeding, they have strained the poisonous
plankton out of the water.

4. Fish and shellfish become toxic when they

A) swim in poisonous water
B) feed on poisonous plants or animals
C) change their feeding habits
D) give off a strange glow
E) take strychnine into their systems

(A) Close, but it's not that the fish swim in poisonous water - it is that the fish eat the poisonous plankton from the plants. Choice B is correct. See Reading Comprehension Strategy 2, p. 136, to practice with the strategy.

(B) You are right. The fish feed on the poisonous plankton, which can be plants or animals. See Reading Comprehension Strategy 2, p. 136, to practice with the strategy.

(C) Don't assume something that is not stated or implied. We have no way of knowing that the fish change their eating habits. The fish feed on the poisonous plankton, which can be plants or animals. Choice B is correct. See Reading Comprehension Strategy 2, p. 136, to practice with the strategy.

(D) Do not make superficial associations. Just because it says that "the meaning of glowing water is ominous," that does not mean that the fish give off a strange glow and then become toxic. The fish feed on the poisonous plankton, which can be plants or animals. Choice B is correct. See Reading Comprehension Strategy 2, p. 136 to practice with thestrategy.

(E) Although poison is the cause, the specific poison is not mentioned in the passage. The fish feed on the poisonous plankton, which can be plants or animals. Choice B is correct. See Reading Comprehension Strategy 2, p. 136, to practice with the strategy.