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问题 单项选择题

下列关于动脉瘤样骨囊肿描述错误的是（）

 

A.属非肿瘤

B.30岁以下少见

C.病骨呈膨胀性，溶骨性破坏

D.T1WI低信号，T2WI高信号

E.可见液－液平面

答案

参考答案：B

填空题

根据图画中物品的位置，用介词on，in，below，beside填空。

1. His pens and pencils are ______ his pencil case.

2. His shoes are _______ his bed.

3. His lamp is _______ his bed.

4. His books are ______ his desk.

5. His coat is _____ his bed.

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单项选择题

萝卜与甘蓝杂交，一般F1是不育的，组偶而也可发现可育的植株，其原因是（）。

A、基因重组

B、基因突变

C、染色体加位

D、染色体畸变
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