推 ck901372:我覺得是因為沒有殼所以藤壺沒有cling to 的地方使得 04/23 01:13
→ ck901372:藤壺種類沒有辦法生長 D完全和burrow無關阿 04/23 01:15
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.
OA: E
Crabs don't burrow----> substantial populations of barnacles.
BUT
In areas where tidal is weak and thus crabs seldom burrow, barnacles
population isn't significant.
(A) tidal currents沒有將baracles逐出crabs的殼--->沒有解釋為何在weak tidal的地區
barnacals沒有這麼多
(B) 說barnacles在tidal weakest的地區容易附著在crabs上--->這樣應該有比較多
barnacles才對!
(C) 說tidal currents的stregth----Irrelevant
想請問(D)和正確選項(E)
(D)不行是因為 說如果barnacles的人口很大會使crab找食物的能力下降
---> 並沒有解釋crab seldom burrow為何barnacles的人口還是很少
請問這樣的思路對嗎?
謝謝!!!!
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