問題詳情

四、閱讀測驗  A cactus仙人掌 is an amazing plant, perfectly suited for living in the hot, dry desert. There are over 1,500 species of cacti, all native to the Western Hemisphere半球. They can be as small as just a few centimeters or as tall as forty feet.It does not rain often in the desert, but when it does, it is usually a downpour lasting only for a short time. The roots of a cactus plant spread very far, but only a few inches below the surface. That way, the plant can absorb a large amount of water in a short time-perfect for the desert cloud bursts. Most cacti have no leaves, but carry on the food-making process過程 in the green stems. Water is stored in the spongy海綿狀 or hollow stem. The skin of a cactus is thick, waxy, and has few pores, helping to retain water. Cacti can live for months, or sometimes even years, without water. Some of the largest may store over 500 gallons of water after a rain.
46.Why don't cactus roots grow deep in the ground?
(A) There is no water there.
(B) The desert is too rocky.
(C) They spread far.
(D) They absorb a large amount of water.

參考答案

答案：C
難度：適中0.5
統計：A(2),B(0),C(3),D(1),E(0)

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