Which of the following is the most important element of Koch’s germ theory of disease? The animal shows disease symptoms when ( )
A: the animal has been in contact with a sick animal.
B: the animal has a lowered resistance.
C: a microorganism is observed in the animal.
D: a microorganism is inoculated into the animal.
A: the animal has been in contact with a sick animal.
B: the animal has a lowered resistance.
C: a microorganism is observed in the animal.
D: a microorganism is inoculated into the animal.
举一反三
- Passage 1 -12 A: He saw another animal behind the dead animal. B: He saw a gun beside the dead animal. C: He saw a man behind the dead animal. D: He saw people behind the dead animal.
- Which animal is not the animal in Chinese Zodiac?
- A rabid animal is most dangerous during the early stage of the disease because______. A: it becomes restless, nervous and violent B: its bite is fatal C: the potential danger of the sick animal may be ignored D: it will attack people at any time
- We should avoid close contact with an animal that has fever and cough.
- The muscles of a fossilized animal can sometimes be reconstructed because______. A: they were preserved with the rest of the animal B: they were lodged inside the animal's skull C: they were hardened parts of the animal's body D: they were attached to the animal's skeleton