20．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

19．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

18．From the passage we know that the evolutionary scale is graded according to 　　　　　.

　　　　 A．evolutionary cycles　　 B．heights and depths　　　 C．time 　　　　　 D．kinds

17．Wood becomes larger because of 　　　　　.

　　　　 A．dead cell walls 　　　　　　　　　　　　　　　　　　　　　　　

B．water entering dead cells

　　　　 C．the growth of cells 　　　　　　　　　　　　　　　　　　　

D．the death of cells

16．Which of the following items is probably allowed in the checked baggage ?

E

All plant cells are capable of taking up water . Even dead ones do to a certain degree . Absorption 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 roots do exist , however . Those greenish-yellow lichens(苔藓)you seen 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 have roots .

Even among the flowering plants , one finds rootless forms . These flowering plants are “the higher plants” because they evolved(进化) recently and are thus considered higher on the evolutionary scale(进化树). In the 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 be of no use , because where the plant grows , it never rains . The plant gets its water only from the dew(露水)it collects 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 the open . If they are placed too near a house , the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming , and the plant dies . In the southern United States and in Puerto Rico , one sees bromeliads growing high above the streets on the insulation(绝缘物)of electric wires . These plants get their water from rain , and the only soil they ever come in contact with is the dust that may blow on their leaves .

15．What is the meaning of “liable” as it is used in the text ?

　　 A．responsible by law 　 B．permitted by law

　　　　 C．suitable by law 　　　　　　　　　　　　　　　　　　　　　　　 D．prepared by law

14．The leaflet is most probably provided by TSA to those who 　　　　　.

　　　　 A．refused to check in their baggage 　　　B．had their baggage selected for inspection

　　　　 C．kept some damaged items in their baggage D．left their baggage unlocked

13．This leaflet (宣传单) is trying to 　　　　　.

　　　　 A．introduce one of the security acts 　　B．persuade people to contact TSA

　　　　 C．inform people of baggage inspection 　D．warn against the damage of locking the baggage

12．Which of the following best explains the meaning of the word “sophisticated” as it is used in the text ?　

　A．Easy .　　　 B．Complex .　　 C．Simple .　　　　 D．Advanced .

D

To protect you and your fellow passengers , the Transportation Security Administration (TSA ) is required by law to inspect all checked baggage . As part of this process , some bags are opened and inspected . Your bag was among those selected for inspection .

During the inspection , your bag and its contents may have been searched for items forbidden by law such as fireworks , fuels , gun powder , etc . At the completion of the inspection , the contents were returned to your bag , which was resealed(重新封口)with a “special” lock .

If the TSA screener was unable to open your bag for inspection because it was locked , the screener may have been forced to break the locks on your bag . TSA sincerely regrets having to do this , and has taken care to reseal your bag upon completion of inspection . However , TSA is not liable for damage to your locks resulting from this necessary security precaution(预防措施).

For packing tips and other suggestions that may assist you during your next trip ,visit :

WWW.TSATravelTips.us　

We appreciate your understanding and cooperation . If you have questions , comments , or concerns ,please feel free to contact(联系)the Transportation Security Administration Consumer Response Center :

Phone : toll-free at (866) 289-9673

Email : TellTSA@tas.dot.gov

*Section 110(b)of the Aviation and Transportation Security Act of 2001, 49, U. S. C.§44901(c)-(e)

11．What can be learned from the passage ?

　　　　 A．33 students were divide into four different groups in the experiment .

　　　　 B．Spell-check software can be of great help to writers and editors .

　　　　 C．With the help of spell-check software those with lower SAT scores will make fewer mistakes .

　　　　 D．Students often make more mistakes in writing if they trust spell-check software too much .