Question

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。

       In this unlikely place, researchers are putting the seeds from flowering plants and trees in a sleeplike state．Many years from now, other workers will wake the sleeping seeds up to plant them

       1  they are most needed．These seeds are  2  the legendary Rip Van Winkle, who fell asleep under a tree and woke up 20 years later．

       The small farm, called the Greenbelt Native Plant Center, is part of a global effort to save  3 （threaten） plants and trees．Around the world, native plants are being crowded out by invasion newcomers．Native plants have less room to grow now   4   a result of the growth and spread of cities．And global warming is making some places hotter, drier, or different from  5   native plants are used to．

       Experts used to think  6  possible to protect big-city plants such as American bittersweet because growth space is limited in urban environments．Crowding increases competition between natives and invaders, and the latter often win the battle．

       7  , scientists have found ways  8  fighting back．So far, workers at the Greenbelt Native Plant center   9   （gather） seeds from about 300 of those plants and put them in a sleeplike state．When  10  （plant） in the future ,these seeds could help restore damaged parkland and forests．

Answer 1

1．where  2．like        3．threatened    4．as            5．what

6．it      7．However   8．of           9．have gathered  10．planted