培训（）的选择是决定培训效果的关键。 A.学生 B.领导 C.教师 D.员工

词语解释。

弈              矣                诲              通国                   

秋                俱              援                   弗                  

常温下交感神经节能耐受完全缺血的时间是（）

A.3～5分钟

B.10～15分钟

C.20～40分钟

D.45分钟

E.60分钟

患儿，女，4岁，因"发现心脏杂音1年伴气促"就诊。查体：体温：37.0℃，血压95／42mmHg，SPO₂98%。双肺呼吸音粗，未及明显啰音，心率102次／分，律齐，心前区可闻及2～3／6级收缩期杂音。超声检查提示：中位心，矫正性大动脉转位，膜周部室间隔缺损直径4mm，三尖瓣反流（中重度），左室壁厚度低于正常值，室间隔偏向左室面。

在对该患儿进行初次肺动脉环缩手术时，合适时左心室压力应达到体循环压力的（）

A.30%

B.40%

C.50%

D.60%

E.70%

F.80%

Imagine fishermen walking down to the seashore, ready to carry out their early morning routine of preparing their boats and net. (51) they hope for a good catch of fish. But to their (52) , a horrible sight meets their still sleepy eyes. Thousands of fish have been washed ashore dead. The cause of this mass destruction—A red tide!

Red tides are a global (53) . They have been observed on both the Atlantic and the Pacific coasts of the United States and Canada. They have also occurred in many other places. Though relatively few people are (54) them, red tides are not new.

In the Philippines, a red tide was first seen in the province of Bataan in 1908. Since then, red tides have been seen in many other (55) . A Philippines red tide expert told us that " (56) the fish kills, the Philippines has documented 1, 926 eases of dead shellfish poisoning caused by red tides. "

The term "red tide" (57) the discoloration of water that sometimes occurs in certain areas of the ocean or sea. Although the color is often red, it may also be (58) of brown or yellow. The World Book Encyclopedia reports that "the discolored areas may range from (59) a few square yards to more than 2,600 square kilometers. "

What causes such discoloration Red tides are generally caused by several species of single-celled organisms. These tiny organisms have hair-like projections which they use to (60) themselves in water.

54().

A. assured of

B. worried about

C. concerned about

D. aware of

简答Bonczek三系统结构的优缺点。