Blue－green algae grow abundantly in salt marshes.

“在一个人采取的所有行为中，如果某一个行为经常获得奖励，则该行为越可能重复出现”。属于人际交换理论基本原则中的

The megaphone(microphone) makes the voice sound louder because it points sound waves in one direction and keeps them from spreading out in all directions.

“他们往往知道双方的秘密，却又似乎是双方的同谋者”，指的是不协调角色中的（）

法律的建立就是为统治阶级的利益服务的，表明的是（）

The first paper was made from the bark of the mulberry tree.

既是研究人际关系的一种方法，又是可以借以评估人际关系的方法是（）

In 1861 it seemed inevitable that the Southern states would break away from the Union.

Some sea urchins海胆 have venomous (toxin) spines

The company issues an annual report every March.