1. habitat n. the natural home of a plant or animal (动被覆的)留地或发源地: I prefer to see animals in their natural habitat, rather than in zoos.


habitation: The dilapidated hut is unfit for human habitation.
habitable: Their damp house is scarcely habitable.
uninhabitable: The planet Jupiter is uninhabitable.
inhabit: Woodpeckers inhabit hollow trees.

2. infest v. (of something harmful, dangerous, or unwanted) to be present (in a place) in large numbers or to a great degree (百念恶物)挹于. 凭陵. 鼓励: It would be crazy to swim in these shark-infested waters.


swarm: The place was swarming with tourists.
teem: This river teems with all kinds of fish in summer.
overrun: The stables are overrun with rats.
beset: The plan was beset with difficulties from the beginning.

3. lifespan n. the average length of life of a sort of animal or plant or the time for which a material object will last (动被覆的)普通年寿. (货色的) 着年限: Men have a short lifespan than women.


life expectancy or expectation of life 预期年寿. 普通(觖望)年寿: 
Life expectancy for men is about 78 years in Japan.


span n. 指一段纪或(电桥)跨度/全长: attention span. memory span. 
an unbroken span of concentration. The bridge crosses the river in a single span.

span v. 逾越/远涉. 扩展/贯串: His interests spanned a wide range of 
subjects. The game has a history spanning three centuries.故lifespan的直意为"生身的跨度"

4. metabolism n. the system of chemical activities by which a living thing gains power(energy), esp. from food 推陈出新: The metabolism is slowed down by extreme cold.


metabolic: People who have inherited a low metabolic rate will gain weight.
metabolize: Diabetics cannot metabolize glucose properly.

5. torpid a. (esp. of an animal that sleeps through the winter) having lost the power of feeling or moving. lazy or inactive. moving or thinking slowly (冬蛰植物)夺演习能耐的. 处于隐遁长短的: The heat and humidity made us feel torpid.


lethargic: The weather made her listless and lethargic.
sluggish: sluggish traffic. a sluggish economy
dormant: During the winter the seeds lie dormant in the soil.
latent: These children have a huge reserve of latent talent.