WS 076
L2
讲座
1. What is the main purpose of the lecture?
To explore present and future uses for desalinated water
To compare the properties of salt water with the properties of freshwater
To evaluate methods of desalinating water
To explain why desalination is becoming increasingly important
2. Why does the professor mention chlorine?
To point out an important difference between seawater and drinking water
To explain why desalinated water contains less disease-causing bacteria than seawater does
To indicate why engineers began using polyamide membranes in the desalination process
To point out a disadvantage of using polyamide membranes in the desalination process
3. What does the professor imply about graphene oxide membranes?
They have already become outdated by more recent advances in technology.
They save money in the long term despite their high initial cost.
They are not as durable as polyamide membranes are.
They require higher water pressure than polyamide membranes do.
4. What points does the professor make about the black aluminum disks that he discusses?（多选题）
They float on water that is being desalinated.
They fracture when exposed to intense sunlight for extended periods of time.
They help prevent evaporation systems from overheating
They make efficient use of the energy in sunlight.
5. According to the professor, what is one disadvantage of all desalination systems
that are based on evaporation and condensation?
They are expensive to operate.
They release contaminated water vapor into the air
They remove beneficial substances from water.
They cannot remove all the salt from seawater.
6. What does the professor imply when he says this:
Floating farms may not be profitable.
Floating farms will not become widely accepted until the public is made aware of their economic value.
The technology developed for floating farms could be useful in many different fields.
Floating farms will play a major role in agriculture in the future.
