og cr 59求解惑

starlitcream

59.   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 aquire 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.

A. Tidal currents do not themselves dislodge barnacles from the shells of horseshoe crabs.

B. Barnacles most readily attach themselves to horseshoe crabs in aeras 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 sheir shells and grow new several times a year.

答案是 E。可是我不明白A为什么不对？

icewaterkira

A的意思是潮汐不会自己把壳上的藤壶弄掉，这样所以不能解决这个题目。我想问是D，D说过多的藤壶会减少螃蟹找食物的能力，这样长藤壶多的螃蟹就会死掉啊。不就能够回答这个问题了吗？