对于多细胞生物而言，下列有关细胞生命历程的说法，正确的是[]

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问题选择题

对于多细胞生物而言，下列有关细胞生命历程的说法，正确的是[ ]

A．缺氧导致脑细胞死亡是细胞坏死

B．细胞癌变是所有细胞都要经历的一个阶段

C．皮肤上的老年斑是细胞凋亡的产物

D．人体各种组织细胞的衰老是同步进行的

答案

答案：A

写作题

书面表达。

仔细观察，根据图示回答下列问题。每小题只限写一句话。

1. What are the students in Picture l doing?

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2. What do the students see while they are on their way home?

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3. What happens to one of the boxes on the truck?

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4. What is one of the students doing after he sees what has happened?

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5. What will the students and the policeman probably do with the wounded driver?

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问答题简答题

区域代码B₂表示什么？