阅读理解 All plant cells are capable of taking up water. Even dead ones do to a cert

阅读理解

All plant cells are capable（有能力的） of taking up water. Even dead ones do to acertain degree. Absorption（吸收）of water by dead cell walls makes wood become larger. In common land plants,the living cells of roots take up most of the water. Land plants without rootsdo exist, however. Those greenish-yellow lichens（苔藓）yousee on rocks in the high mountains have no roots. Half a billion years ago,when water plants started to enter the land, the first land plants did not haveroots.

Even among the flowering plants, one findsrootless forms. These flowering plants are “the higher plants” because theyevolved（进化） recently and are thus consideredhigher on the evolutionary scale（进化树）.Inthe Peruvian desert, there grows one of these rootless higher plants, a bromeliad.It is a relative of the pineapple. Even if this plant had roots, they would beof no use, because where the plant grows, it never rains. The plant gets itswater only from the dew（露水）itcollects at night, when its leaves cool off. Such rootless plants, of course,can be moved with ease, but they will only grow when they are placed out in theopen. If they are placed too near a house, the radiation from the heat of thehouse prevents the leaves from cooling and so prevents dew from forming, andthe plant dies. In the southern United States and in Puerto Rico, one seesbromeliads growing high above the streets on the insulation（绝缘物）of electric wires. These plants get theirwater from rain, and the only soil they ever come in contact with is the dustthat may blow on their leaves.

1.Wood becomes larger because of ______.

A. dead cell walls

B. water entering dead cells

C. the growth of cells

D. the death of cells

2.From the passage we know that the evolutionary scale is gradedaccording to ______.

A. evolutionary cycles

B. heights and depths

C. time

D. kinds

3.The “bromeliad” is a plant that ______.

A. has useless roots

B. is a pineapple

C. can grow anywhere

D. takes up water through its leaves

4.The most suitable title for this passage is “______”.

A. Absorption of water by plants

B. Rootless plants

C. Plants in the desert

D. Higher plants

试题答案

答案：1B2C3D4A