关于受精过程恰当的是（）
A.精子与卵子相遇，标志受精过程已开始
B.精子获能的主要部位是 * *
C.精子与卵子相遇时发生顶体反应
D.卵子停留在输卵管峡部等待受精
E.精原核与卵原核融合，标志受精过程即将完成
参考答案：C
解析：卵子停留往输卵管壶腹部与峡部连接处等待受精；精子获能的主要部位；是子宫和输卵管；已获能的精子穿过次级卵母细胞透明带为受精过程的开始；卵原核与精原核融合为受精过程的完成。
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| A man wanted to make an investment (投资). An idea struck him:"Why don't I plant a small mango tree and enjoy the benefits when it grows into a big one?" So he went to the __1_, bought a small tree and took it home. To the pride of his family, he _2_ it in the center of his __3_. He read everything about _4_ a mango tree. He got up early every morning, for he was determined to supply the tree with all the necessary nutrients. He watered it, _5_ it with manure (粪肥), and took good care of its leaves by removing those _6_ ones. He made sure the tree received enough care. Many times he sat and _7_ the beauty of the growing tree while dreaming about the _8_ mangoes that the tree would _9_. His mind was always filled with the wish to taste the first fruit of the tree. Years went by 10 …now, he had a big tree with its leaves shining and healthy, its bark healthy and hard. It was a big attraction 11 it decorated his whole garden. Then one day he noticed a small bud (花蕾), which in a couple of days grew into a beautiful 12 . Now he could 13 wait for the fruit so he started to increase his supply of nutrients and care. Then one day the tree let out its first product-a small green fruit. The man was so 14 . He waited for a few more weeks till the fruit grew in 15 . The day came when he decided to 16 the first fruit of the tree. He 17 the tree, picked the fruit and then came his 18 . The fruit was not like what he expected. It was hard, big and round. He was puzzled. He was sad. Seeing this, his 19 came and asked him what happened. He told them that the fruit from his tree was not what he wanted. When the neighbours heard this, they did not know whether to 20 or comfort him, for what he planted years ago was not a mango tree. We can only reap (收获) what we plant. | ||||
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