题目内容：

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Visitors to the dry, hot Sonoran Desert of the southern Arizona and northern Mexico are amazed at the many­armed giants. They are the saguaro cacti (树形仙人掌), a giant which gives the landscape its _____________ appearance. In the dry desert the saguaro cacti can live for more than 200 years, grow to a ___________ of 60 feet, and have as many as 50 arms.

More __________， the saguaro cacti still persist despite the unbearable desert climate. Those that have grown to old age have ___________ droughts, freezes, flash floods, and bush fires as well as the ___________ caused by groups of rats that eat their seedlings (秧苗). Like all other desert ___________， these leafless giants can store water for use during the desert's long dry seasons by ____________ water through their long roots.

Naturally, the great saguaro cacti are a(n) __________ part of the desert life. Actually the giants may be ___________ to many animals, including woodpeckers, owls, doves, bats and insects. In addition, after a saguaro __________ the age of 50 or so, cold­resistant flowers ___________ at the top of the plants once a year. These flowers ____________ birds, bats and bees, which come for the honey and for the tasty flowers with their black seeds.

___________ the splendid saguaros are plentiful in the Southwest, they are unfortunately ___________. These giant cacti have great value in landscape gardening, and the thieves can earn thousands of dollars by uprooting and __________ them to nurseries (苗圃). To protect these southwestern ___________， agents for the Arizona Department of Agriculture go around and __________ the desert. It's a most important job though a hard one. But without the saguaro cacti, many desert animals would suffer a lack of __________ and loss of nesting sites. The Southwest, too, would ____________ something of unique importance, since these desert giants have become a ____________ of the dry region.

1.A.general          B．basic             C．unique                 D．lovely

2.A.length             B．height            C．size                   D．width

3.A.pleasingly         B．inspiringly       C．interestingly          D．amazingly

4.A.lived through      B．broken through    C．cut through            D．got through

5.A.crisis             B．damage            C．destruction            D．load

6.A.plants             B．lives             C．animals                D．creatures

7.A.pouring            B．squeezing         C．pumping                D．absorbing

8.A.independent      B．vital             C．original               D．mysterious

9.A.spot               B．field             C．home                   D．camp

10.A.turns             B．takes             C．meets                  D．gains

11.A.come up           B．come out          C．show off               D．show up

12.A.call              B．trap              C．fascinate              D．stick

13.A.As                B．But               C．Although               D．Yet

14.A.in danger         B．in demand         C．in need                D．in control

15.A.exchanging        B．trading           C．offering               D．selling

16.A.treasures         B．decorations       C．possessions          D．creations

17.A.look over       B．hand over         C．watch over           D．turn over

18.A.food            B．scenery           C．water                  D．flavor

19.A.affect            B．abandon           C．increase             D．lose

20.A.signal           B．sign              C．mark                   D．symbol