Mum, why have us eat much vegetable? —Because it is _____ to our health.

It’s impossible for ____ few people to finish ____ a lot of work in only two days [ ]

The companies are working together to create ________ they hope will be the best means of transport in the 21st century.

People are warned ________ in that city because there is some virus going around the city.

We can gain valuable experience from the mistakes which _____ to prevent them from happening again.