烧杯中的一大块冰内含有一定量的砂子，冰块漂浮在水面，杯中水面恰好与杯口相平，且冰

Many scientists believe that life begins in the ocean long ago. For age man used the ocean to discover and explore new lands. Now man spends a great deal of time or money discover the ocean. We know it is rich at minerals which the world need. We know too that it contains a plenty of food for all the people in the world. We know that if the salt were taken from it, it’s water would turn the deserts into rich farm lands. We know a great deal about this land frontier, as it has called. But we still need to learn many more about it.

缝衣针

孤独症的康复，核心部分是任务分解技术的是（）

A.评定技术

B.结构化教育

C.听觉综合训练

D.感觉综合训练

E.应用行为分析疗法

原发性三叉神经痛的患者可能出现的体征（）。

A.患侧面部感觉减退

B.患侧咀嚼肌萎缩

C.患侧角膜反射消失

D.患侧面部可有触发点

E.张口时下颌偏向患侧

使脑血流量突然、短暂性减少的最危险因素是（）

A、外周血管扩张

B、心排血量突然下降

C、椎基底动脉供血不足

D、突然站立时血液分布不均

E、脑血管广泛痉挛