One way to reduce your carbon footprint is to use ______________ , or better still, zero-carbon biofuels.

Biofuels are classified as a _______________ energy source because they come from plants and trees, which can be grown again and again.

We should reduce the amount of possessions we have.

Seemingly, people prefer to buy locally, if possible.

It __________________ that people prefer to buy locally, if possible.

Bill’s visit to the theme park ___________ memories of his childhood.

All my plants seem to die quickly. I clearly don’t have a _____________ .

Economics _______ the study of how people and organizations allocate scarce resources.

Why is the ocean blue? It is not, as people think, because it is a reflection of ______ sky, but is in fact because _________ atmosphere tends to scatter blue light more than red light. So when you look at the sky in the day, you see blue no matter where you look. So why is some water bluer than other water? ________ simplest answer is that the water is shallower and the sunlight reflects off the sand beneath it.

Wikipedia is a great example of a _____________ technology – one that improves a product or service in a way that the market does not expect. The arrival of Wikipedia was a huge ___________ to the educational industry because it offered its content for free.

Due to ___________ circumstances, we had to postpone our vacation.

I really think it would be a good idea if Jane took her work more seriously.

I suggest that __________ her work more seriously.

Large parts of Australia are reported __________________ devastating heatwave conditions last week, and the sizzling temperatures are known _______________ several major cities across the country.