问题补充：
Trees are one of the oldest plants on the earth. Just like us, trees change a lot 1they grow. At one to three years old, young trees learn to 2themselves. For example, many tree grow thorns (刺)to tell animals 3near. Most young trees have large and deep green leaves to 4enough sunlight and turn it into their food and energy. When trees are four years old, they arestrong enough to 5the challenge(挑战)in life. At the age of fifteen, they become young adults and grow more 6. They will have their own flowers and fruit. After the trees are twenty to twenty-five years old, they are called real adults because they reach their 7. Adults trees give us oxygen and natural beauty. If we 8them very well, they will live healthily for many years. As time goes on, trees begin older and older and even 9. At this time, they still have their important places in nature and uses for people. 10many ways, the life of trees is like our own life experience.
【小题1】A．beforeB．when C．after D．since【小题2】A．protectB．provideC．prevent D．pollute【小题3】A．to goB．to leaveC．not to goD．not to leave【小题4】A．enjoyB．keepC．stay D．catch【小题5】A．getB．receiveC．face D．welcome【小题6】A．fastB．fasterC．slow D．slowly【小题7】A．weightsB．heightsC．styles D．sizes【小题8】A．look forB．look after C．look outD．look at【小题9】A．dieB．hurtC．wasteD．throw【小题10】A．OnB．InC．ForD．AtB
答案：
(答案→)B
解析：
【小题1】根据句子的意思，可知答案为B，表示当…时候，故选B
【小题2】根据下文的内容，故选A
【小题3】tell sb （not）to do sth，根据文章意思，故选C
【小题4】根据意思可知，所有的植物能够抓到更多的阳光，故选D
【小题5】根据文章的意思可知答案为C，表示为面对的意思
【小题6】根据常识可知答案为D
【小题7】根据上下文的内容可知答案为D
【小题8】根据上下文的需要可知答案为B，表示照顾的意思。
【小题9】根据前文的内容可知答案为A
【小题10】in many ways表示在某些方面，为固定词组搭配。
