问题
选择题
丽丽种在自己家密封良好的阳台上的黄瓜开了许多花，却没有结出一条黄瓜．请你帮她分析原因（ ）
A．光照不足，营养不足
B．黄瓜的花无花蕊
C．室内不通气，缺乏氧气
D．没有昆虫，不能传粉
答案
黄瓜是进行异花传粉的，且主要依靠昆虫传粉，在封闭良好的温室中的黄瓜，室内没有昆虫，没有昆虫为其传粉，从而降低传粉和受精的机会，出现只开花不结果．
故选：D
搜题请搜索小程序“爱下问搜题”
丽丽种在自己家密封良好的阳台上的黄瓜开了许多花，却没有结出一条黄瓜．请你帮她分析原因（ ）
A．光照不足，营养不足
B．黄瓜的花无花蕊
C．室内不通气，缺乏氧气
D．没有昆虫，不能传粉
黄瓜是进行异花传粉的，且主要依靠昆虫传粉，在封闭良好的温室中的黄瓜，室内没有昆虫，没有昆虫为其传粉，从而降低传粉和受精的机会，出现只开花不结果．
故选：D
One day there was an argument between the wind and the sun. "I'm much 26 than you," said the wind. "No, I don't agree with you!" said the sun. While they were arguing, they saw a man 27 along the road. He is wearing a heavy coat. The sun said to the wind," Now, let 28 see who can make the man take 29 his coat. Then we will know who is stronger." First the wind tried. It began to blow very hard. It blew 30 hard that the man pulled his coat around him. The wind was 31 with the man. Then it said to the sun," Now, it's your 32 ."The sun started to 33 on the man. Soon it got very 34 ! The man took off his coat. The argument was over. We know the 35 was stronger now.
|