题目
Biological treatment may use __ to treat sewage (1)living organisms (2)chemicals (3)additives
A.(1)
B.(2)
C.(3)
D.(1)(2)(3)
第2题
A.agitation function
B.bacteria
C.chemica
D.oxidizing function
第3题
A.aeration tanks
B.settling tanks
C.disinfection agent(消毒剂
D.anaerobic bacteria(厌氧菌)
第4题
A.aeration(通风) tanks
B.settling tanks
C.disinfection agent(消毒剂)
D.anaerobic bacteria(厌氧菌)
第5题
第三组:
The sewage treatment system must be capable of discharging an effluent that comes within the limits of the tests. Sewage can be treated biologically so that it may be discharged with minimal damage to ecosystem. Biological treatment involves the use of living organisms to treat the sewage within the sewage treatment plant so the liquids and sludge discharged are within the standards specified.
Biological treatment plants are usually built up as a module and consist of various sections.
Waste matter collected from the ships sanitary appliances is led through a sanitary piping system to the treatment module. The solid matter is broken up by passing it through a screen or a series of revolving cutters. The broken up solid material, together with the waste liquid, passes into a tank containing bacteria which require oxygen and a nutrient to propagate. The nutrient is contained in the solid waste material, and oxygen is supplied by bubbling compressed air through the broken up waste. The propagated bacteria change the waste material into a sludge by aerobic digestion. The sludge is finally treated to kill the coliform. bacteria before it is passed overboard.
When a biological sewage plant is started up, such as when activating a new ship or after cleaning out the tank, a pellet containing bacteria is introduced into the tank. It takes approximately one week for the bacteria to propagate and make the system fully effective. The choice of sanitary appliance cleaners requires extreme care, as many cleaners are toxic to the active bacteria. Once a biological sewage plant is made active it should not be shut down. If it is it will have to be reactivated again because the bacteria will die without a supply of nutrients and oxygen.
Bacteria that require oxygen for their survival are referred to as aerobic. Aerobic bacteria are normally used in ships&39; sewage treatment equipment. Other forms of bacteria that do not require oxygen are referred to as anaerobic. Anaerobic bacteria are used in shore based sewage treatment works where methane is obtained as a by-product for use as fuel.
This passage is mainly about
A.sewage treatment methods
B.the various sections of a sewage treatment plants
C.biological sewage treatment system
D.how the sewage treatment plants are started up
第6题
填句补文
Biological Clock
When the sun rises on a warm and sunny day, you can see some flowers open up. When they close late in the afternoon, other flowers open.
Biological rhythms(生物节律), like the opening and closing of flowers, happen all over nature. But not all of them are daily rhythms. Some, like the beating of our heart, happen every second. (1)Scientists use the term biological clock to describe the timing that controls biological rhythms. (2) In some animals it is probably controlled by the brain. In plants and other living things that have no brain, it must be something else.
The migration of animals happens when a signal is sent out. For example, when days become shorter, birds leave the northern parts of the world and fly south where it is warm. (3)Humans also have biological clocks that control their daily rhythms. When people travel by plane from one continent to another, they often cross many time zones. Their internal clocks don’t seem to work correctly. We call this jet lag(时差). (4)People who work night shifts also have problems with their biological clocks. They may not be as active as people who work during the daytime.
Biological clocks control many rhythms of life. (5) Doctors are looking for new ways to make travelling more comfortable and medical treatment more effective.
A. But where can you find it?
B. This makes them feel tired.
C. In the summer they fly back to have babies.
D. We are learning more and more about them.
E. Biological clocks can be adjusted.
F. Other rhythms are based on months, seasons or years.
第7题
B.This makes them feel tired.
C.In the summer they fly back to have babies.
D.We are learning more and more about them.
E.Biological clocks can be adjusted.
F.Other rhythms are based on months, seasons or years.
______.A.But where can you find it?
B.This makes them feel tired.
C.In the summer they fly back to have babies.
D.We are learning more and more about them.
E.Biological clocks can be adjusted.
F.Other rhythms are based on months, seasons or years.
______.A.But where can you find it?
B.This makes them feel tired.
C.In the summer they fly back to have babies.
D.We are learning more and more about them.
E.Biological clocks can be adjusted.
F.Other rhythms are based on months, seasons or years.
______.A.But where can you find it?
B.This makes them feel tired.
C.In the summer they fly back to have babies.
D.We are learning more and more about them.
E.Biological clocks can be adjusted.
F.Other rhythms are based on months, seasons or years.
______.A.But where can you find it?
B.This makes them feel tired.
C.In the summer they fly back to have babies.
D.We are learning more and more about them.
E.Biological clocks can be adjusted.
F.Other rhythms are based on months, seasons or years.
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