达人帮忙把这段视频里的台词用文字打出来```

问题补充：网址无毒
题目是HOW 2 MAKE DRINKING WATER

花我好半天.查了不少词...
有些英文地方不看视频不会太明白的.

Drinking water that’s fresh, clean, and crystal clear, is something many of us take for granted. We might not give it a second thought, but between the source and our tap(水龙头), a lot happens to make that water fit to drink.

All water may come from other nature, but it’s far from pristine(纯净的). It starts its journey to the treatment plant(plant这里不是植物的意思,是指工厂) through the water intake pipe. On the wall of that pipe, about 2 meters down, is a 15 centimeter hole. Covering that hole is a medal grill designed to keep out large debris(碎片) such as tree branches.

The water flows to a pumping station, where it goes through preliminary screening. A giant revolving screen removes fish, garbage and grass.

Once they remove the debris, a low-pressure pump moves the water into the treatment plant. The untreated water, called raw water, is dirty and smelly. So they first add a powerful form of the chemical element carbon, called activated carbon filter. It absorbs contaminants such as sulf(应该是指sulfur) and pesticides(杀虫剂). That rids the water of the bad taste and odor.

From there the water then goes through a series of mixing tanks. The first tank holds a chemical called aluminum sulfate; it acts as a coagulant(凝结剂), a substance that thickens liquid into globs(glob=一团).
In the raw water, the aluminum sulfate forms tiny globs called “flocs”(flocculus的简称.意思是絮凝物). Bacteria, mud, and other impurities stick to those flocs. Then the flock-filled water moves on to the second mixing tank.

The second mixing tank holds a chemical called polymer, which is essential to the next step of the process called sedimentation(沉淀). 5 pipes inject the water with super fine particles of sand called “microsands”. The polymer coats the sand, making it sticky. The grains of sand then stick to the flocs of the raw water, weighing them down even more. The water then flows into a settling tank where the flocs, because they’re heavier, settle to the bottom. You can see the result in this demonstration.
The water is finally clear. But it’s far from drinkable because it’s still full of bacteria, viruses, and other organic matter. So we’ll go on to the next step, filtration.

The water flows onto the top of the filter, then trickles downwards, passing through a layer of anthracite, a type of coal, then through a layer of sand. This filters out any remaining particles, which then flows to the middle. But the water is still teeming with bacteria and viruses so it has to be disinfected. They add 1.9 milligrams of chlorine per liter of water, enough to kill off those germs and bugs. They add a mineral called silicate to prevent calcium build up from blocking our water pipes.

The treatment plants sends water samples to government and inspectors, who continuously monitor the water supply to insure it meets safety standards. The amount of chlorine remaining in our drinking water is 0.6 milligrams per liter. The chlorine gas the plant uses is highly toxic, should any leak out, emergency teams would have to evacuate at 10 kilometer radius. So the plant stores the drums of chlorine in a high security area.

It’s taken about 45 minutes to turn raw water into treated water. Now these electric motors will pump it through underground pipes right to your taps.