A Max and Jill are talking about solar paint. Complete their conversation with the correct forms of the words in brackets.
Max: Hi, Jill! I just read an interesting article about solar paint.
Jill: Solar paint? What's that?
Max: It's a kind of clean energy technology. You use it just like regular paint. But once it's on a surface, the paint collects solar energy, like solar panels do. Scientists in this field think solar paint $^{(1)}$ (use) on all kinds of surfaces soon!
Jill: Like what?
Max: Well... it $^{(2)}$ (paint) onto buildings. Then, energy from the sun $^{(3)}$ (collect) by solar paint. We'll use that energy to produce electricity in the buildings. Just imagine: all buildings $^{(4)}$ (power) by solar paint!
Jill: Wow! That sounds amazing! $^{(5)}$ solar paint (put) on other surfaces too?
Max: Yes, it will! Cars, roads and even computers $^{(6)}$ (cover) with solar paint one day. Phones too! With solar paint on our phones, chargers $^{(7)}$ (not need) anymore.
Jill: So cool! Can we already buy solar paint?
Max: Not just yet. Scientists are still experimenting with it. But I think it $^{(8)}$ (produce) for customers within the next few years.
Jill: I can't wait!

B Katie is reading an article about body heat harvesting at a train station in Sweden. Complete it with the correct forms of the words in the box.
collect produce send waste design reduce turn use

It's 8 a.m. at Stockholm Central Station, one of the busiest train stations in Sweden. Thousands of people are passing through on their way to work or school. With so many people moving around, a lot of body heat $^{(1)}$ at the station every morning. Although we produce body heat all the time, this great source of energy $^{(2)}$ usually . But here, at Stockholm Central Station, it is collected. And soon, it $^{(3)}$ into energy.
This system for harvesting body heat $^{(4)}$ by local engineers more than 10 years ago. It collects body heat and uses the heat to warm water. The hot water $^{(5)}$ to a nearby building. There, it provides heat for the building and lowers energy costs. This successful system $^{(6)}$ by more buildings in the city as the need for clean energy increases.
Other cities can learn from Stockholm Central Station. In the future, body heat $^{(7)}$ from busy public places all over the world. As the use of body heat energy becomes more common, our need for traditional energy sources $^{(8)}$ .