If oil supplies run out in 2050 then we need to find ______ energy sources soon.

I don't think Peter will reject that job offer, ___________?

My dog as well as my cats ______ twice a day.

If it had not rained last night, the roads in the city ______ so slippery now.

You are allowed to go to the party ______ you don’t stay out too late. Remember to be back here no later than 11.30 p.m.

More and more investors are pouring money into food and beverage _______ start-ups.

Businesses will not survive ______ they satisfy their customers.

Extinction means a situation ______ a plant, an animal or a way of life stops existing.

The temperature ________ takes place varies widely from material to material.

It seems that you are right, ______?

There has been little rain in this area for too long, ______?

An international menu _____ a variety of food can attract most of the tourists.

In developed world, there are hardly _______ jobs left which don’t use computers to carry out many daily tasks.

______ humans, dolphins use a system of sounds and body language to communicate, but understanding their conversations is not easy for humans.

By the time Brown's daughter graduates,_______retired.

A survey was ________ to study the effects of mass media on young adults.