题目内容：
Which of the following is the smallest in size?
A．Viruses． B．New filters．
C．Living cells．
D．Chemical molecules．
参考答案：
答案解析：
单选题：Which of the following is the smallest in size?
- 题目分类：公共英语二级
- 题目类型：单选题
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B．New filters．
C．Living cells．
D．Chemical molecules．