非特异性投射系统的特征是A．感受器发出的冲动，沿特定的传入通路投射到大脑皮质特定区域

下面有关报道，不符合科学事实的是

A．疏通煤气管道时，充入氩气引起火灾并发生爆炸

B．梅雨季节，一内部被虫蛀空的老柳树突然起火，烧毁

C．有易燃、易爆物的工作场所，严禁穿化纤衣物

D．一老汉因拉亮电灯，寻找煤气漏气处而引发大火，并引起爆炸

下列国家自西向东排列，正确的是（　　）

A．缅甸、泰国、老挝、越南

B．越南、老挝、泰国、缅甸

C．越南、泰国、老挝、缅甸

D．缅甸、老挝、泰国、越南

用所给词的适当形式填空。

1. If you work hard, you will be ___________(success).

2. Those workers spent ten months _____________(build) that bridge.

3. They often find it difficult ___________(learn ) English.

4. Pollution is one of the most serious _______ in the world (problem).

5. I had enough time_______(work) out that math problem.

6. The doctor told me to give up _______ (smoke).

7. I want _______(play) the piano in the evening.

8. We should stop_______(throw) about in public.

9. The knife _______(use) to cut things.

10. I think English is very _______(help) to know about the world.

汽轮机叶片的损坏主要有（）。

A、疲劳断裂

B、脆性断裂

C、硫腐蚀

D、氢腐蚀