1，复习
1，hygiene,the degree that clean yuor environment
2,ideology,the beliefs that one group believe.
3,infrared,light at the red end of spectrum
or
light feel warm but can seen.
4,laureate,a person be given great honor because their ability.
5,mammoth,
adj,very big
n,mammoth elephant.
6,mania,a kind of desire especially many people have.
7,muggy, unpleasantly warm and contain water.like summer weather.
8,prevailing,
adj popular ,or exist in particular time ,particular place.
prevailing wind ,盛行风。
9,prohibitively,in a wat that you can not do that.
10,proofread,find and correct mistakes in text.
11,quota,a fixed number that officially allowed.
12,rampant,getting worse and in a uncontrolled way.
13,ratio,rate.
14,recital,performance of a musician.
15,rash,reckless.
16,restoration,the process of restore..return to a good condition.
17,rodent,啮齿动物;
18,scuba,swimming underwater with breathing equipment.
19,sendimentary,sediment...沉积的
20，sewage,the dirty water in the drain.
21,silt,the sand and soil at the botto of the river.
22,stripe,line line different color.
23,tritutary,a river that flow into a larger river.
24,treadmill,boring work.
25,undertaking, a,a job or business(especially hard)
26,vigilance,carefulness.
27,wane,become weaker usually in plant.
28,amenity,infrastructure.
29,avalanche,the outbreak of mang snow.
30,bolster,inprove,strength.