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.

7. It can be assumed that "plankton" in line 5 are

A) fish and shellfish
B) small plants or animals
C) sand deposits
D) land parasites
E) glacier or rock formations

(A) Watch out for "luring" associations. Plankton seem to come from plants and they are either plants or animals which are attracted to the plant. They would not be fish or shellfish since fish and shellfish are differentiated from coastal plankton in the phrase, "comes to alter the coastal plankton, some of the fishes and shellfish in the vicinity become toxic." If "coastal plankton" were fish and shellfish, the phrase should read, "comes to alter the coastal plankton, some of the coastal plankton in the vicinity become toxic." (You would not substitute "fishes and shellfish" for "coastal plankton.") Choice B is correct. Plankton seem to be small plants or animals, and since the fish feed on them, what else could they be? See Reading Comprehension Strategies 1 and 5, p. 136 and 140, to practice with the strategy.

(B) You are right. Plankton seem to be small plants or animals, and since the fish feed on them, what else could they be? See Reading Comprehension Strategies 1 and 5, p. 136 and 140, to practice with the strategy.

(C) How would fish and shellfish feed on "sand deposits?" Choice B is correct. Plankton seem to be small plants or animals, and since the fish feed on them, what else could they be? See Reading Comprehension Strategies 1 and 5, p. 136 and 140,to practice with the strategy.

(D) Pay attention to the context of the environment that you are in. "Land parasites" would not occur in the water. Choice B is correct. Plankton seem to be small plants or animals, and since the fish feed on them, what else could they be? See Reading Comprehension Strategies 1 and 5, p. 136 and 140 ,to practice with the strategy.

(E) How could fish feed on "glacier or rock formations?" Choice B is correct. Plankton seem to be small plants or animals, and since the fish feed on them, what else could they be? See Reading Comprehension Strategies 1 and 5, p. 136 and 140, to practice with the strategy.