Q33:
In order to withstand tidal currents, juvenile horseshoe crabs frequently burrow in the
sand. Such burrowing discourages barnacles from clinging to their shells. When fully
grown, however, the crabs can readily withstand tidal currents without burrowing, and
thus they acquire substantial populations of barnacles. Surprisingly, in areas where tidal
currents are very weak, juvenile horseshoe crabs are found not to have significant
barnacle populations, even though they seldom burrow.
Which of the following, if true, most helps to explain the surprising finding?
A. Tidal currents do not themselves dislodge barnacles from the shells of horseshoe
crabs.
B. Barnacles most readily attach themselves to horseshoe crabs in areas where tidal
currents are weakest.
C. The strength of the tidal currents in a given location varies widely over the course
of a day.
D. A very large barnacle population can significantly decrease the ability of a
horseshoe crab to find food.
E. Until they are fully grown, horseshoe crabs shed their shells and grow new ones
several times a year.
Answer: E
感觉给出的答案一点关系没有。请朋友们帮忙分析分析 |