设A是n阶正定矩阵，α1，α2，α3是非零的n维列向量，且．证明α1，α2，α

用所给动词的适当形式填空。

1. Let my brother _______ (help) you.

2. Look! Jeff with his friends _______ (play) basketball happily on the playground.

3. Is it fine today? No, it's _______ (cloud).

4. How many _______ (umbrella) can you see in the shop?

5. She wants _______ (drink) a cup of coffee.

6. There are a lot of _______ (cloudy) in the sky at the moment.

7. My pen pal is an _______ (America) girl.

肝硬化所致消化道出血，抢救出血性休克的措施中，下列哪项是错误的

A．建立静脉通道

B．烦躁者给予吗啡或巴比妥类药物

C．保持呼吸道通畅

D．积极补充血容量

E．监测生命体征的变化

简述我国农机农艺融合的原则及保障措施。

使用白盒测试方法时，确定测试数据应根据指定的覆盖标准和______

A．程序的内部逻辑
B．程序的复杂结构
C．使用说明书
D．程序的功能