VOR的基本工作原理是比较（）。 A.基准30Hz信号和可变30Hz信号的相位 B.

把方程x（x+2）=3（x﹣1）化成一般式ax²+bx+c=0，则a、b、c的值分别是 [ ]

A．1，﹣1，3

B．1，1，3

C．1，5，﹣3

D．1，﹣1，﹣3

如果两个相似三角形的面积之比是9：16，那么它们对应的中线之比是______．

句型转换。

1. David often goes to movies with friends on Sundays. (改为一般疑问句)

    _________ David often _________ to movies with friends on Sundays?

2. My mother has some sugar in her bag. (对划线部分提问)

   _________ _________  sugar _________ your mother _________ in her bag?

3. I think hamburgers are very popular in China. (否定句)

    I _________ _________ hamburgers are very popular in China?

4. There were two teaspoons of salt on the plate. (对划线部分提问)

    _________ _________ _________ of salt _________ _________  on the plate?

5.Can you tell me how to make an apple shake? (改写同义句)

    Can you tell me _________ I can _________ an apple shake?

儿童出现黄疸最常见于（）

A.肝炎

B.脂肪浸润

C.胆管闭锁

D.肝硬化

E.肝血管瘤

如AFP超过（）μg/L，谷丙转氨酶基本正常，意味着可能存在肝癌（）

A.100

B.200

C.300

D.400

E.1000