【单选题】Successful scientists have often been people with wide interests. Their originality may have derived from their diverse knowledge. Originality often consists in linking up ideas whose connection was n...
【单选题】听力原文: The rattlesnake, often considered the deadliest of all North American snakes, has often been the subject of research and discussion among naturalists. This snake earns its name from the presence...
A.
The rattlesnake is a dangerous snake.
B.
The rattlesnake's rattles are rings of hardened skin.
C.
The rattlesnake is the only species of snake that has rattles.
D.
The rattlesnake is one of many poisonous snakes that give warning before they strike.