找考题网-背景图
单项选择题

A.Planktons are too small to be seen.B.Most planktons h……

Questions 23 to 25 are based on the conversation you have just heard.

A.Planktons are too small to be seen.
B.Most planktons have transparent tissues.
C.Most planktons are practically invisible to predators.
D.Planktons are fascinating organisms.