Section 3

I

Did your experiments go well?//

K

They were not always successful.// I was looking for a photocatalyst/to put in plastic water bottles.// A photocatalyst was the key/to speeding up the purification process.// It wasn’t easy/to find a new material for it.// But I finally found one.//

I

What’s the material?//

K

It’s a mixture/of cement and a kind of metal.// It’s effective/for speeding up the process.// In addition,/the material is so flexible/that it can be formed/into different shapes and sizes.// Without this flexibility,/it wouldn’t fit/in many different containers.//

I

In what kinds of containers/can it be used?//

K

It can be used/in not only small, personal bottles,/but also large water tanks.//