受精过程中，两个精子进入胚珠是通过（ ）
A．花丝
B．花粉管
C．花药
D．雄蕊
雌蕊的结构包括柱头、花柱、子房．当花粉落到雌蕊的柱头上后，在柱头黏液的刺激下，花粉萌发生出花粉管，花粉管穿过花柱到达子房内的胚珠的珠孔后，花粉管前端破裂释放出两个精子，其中一个精子与珠孔附近的卵细胞融合，形成受精卵．另一个精子与中央极核融合形成受精极核．因此，受精过程中，两个精子进入胚珠是通过花粉管进入的．
故选：B
A clique(小圈子,派系) is a group of friends who hang out together and act in similar ways. Cliques are common feature of the teen years. Members of a clique usually have certain things in common. For example, they might all be good students. Membership in a clique is limited. Not everyone who wants to belong can join. Cliques can have a positive or negative influence. Because most teens have a strong need to belong, they want to feel that they fit into a group. Cliques can help them meet this need. Sometimes teens feel unsure of themselves, and they use a clique to gain approval of what they wear or how they act. Cliques can become harmful, however, if they pressure members to behave the same way as the group that may damage their health. Cliques may discourage members from making their own decisions, giving their own opinions, or having other friends who aren’t accepted by the clique. Cliques may even pressure members to act in ways that go against their own values and beliefs, such as lying to parents or teachers. Cliques can also hurt people outside the group. For example, members might make fun of a teen who isn’t in the clique. If you find yourself under this type of pressure from a clique, here are some actions you can take to improve your situation. ● Suggest other activities. Offer ideas that don’t involve hurting others or putting anyone at risk. ● Find new friends. If staying in the clique is becoming a negative experience, you will be better off with new friends. 小题1:Why do teens want to be a member of a clique?
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