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【单选题】
做“研究远视眼的矫正”实验时，他把凸透镜看作是眼睛的晶状体，光屏看作是眼睛的视网膜，看作是眼睛观察的物体．拿一个远视眼镜放在凸透镜前，光屏上出现清晰的像，如图所示．而拿走远视眼镜则的像变得模糊，下列操作能使光屏上重新得到清晰像的是（ ）A.
将光屏适当靠近凸透镜
B.
将蜡烛适当靠近凸透镜
C.
同时将光屏和蜡烛适当靠近凸透镜
D.
将光屏适当远离凸透镜或将蜡烛适当远离凸透镜
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举一反三
【单选题】All of the following statements about corporations are true except _____.
A.
Corporations are generally more expensive to form than sole proprietorships
B.
The death of owner of a corporation does not terminate the company
C.
Any of the owners has the duty of hiring professional managers
【多选题】下列对玉米螟的描述正确的是( )。
A.
多食性害虫
B.
初孵幼虫啃食叶肉，留下表皮，俗称“花叶”
C.
钻蛀纵卷的心叶，心叶展开后，在叶片上形成整齐的横排圆孔，俗称“排孔”
D.
以老熟幼虫在寄主植物的茎秆、穗轴和根茬中越冬
【简答题】玉米螟俗称玉米钻心虫。属（）目、（）科，是世界性害虫。
【简答题】听下面一段材料，回答第1-3题。 1. What does the two speakers say about Professor Dickinson? A. His study is full of books. B. He often assigns too much reading homework. C. His lecture is very boring. 2. What was t...
【简答题】玉米螟俗称玉米钻心虫，是（）目害虫。
【单选题】Passage 2Directions: Read the following passages carefully. Each passage is followed by some questions or unfinished sentences. For each of them there are four choices marked A, B, C, and D. Choose th...
A.
Color is actually everywhere.
B.
Color is sometimes frightening.
C.
People find it difficult not to use colors.
D.
People have discovered all kinds of colors.
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