Can you help me, please? I can't see the differences .......... these words.

.......... the past, people did a great deal of work by hand.

Is the United States the wealthiest country ______ the world?

They have been waiting ......... the bus for half an hour.

Bluegrass music is some what different ______ other types of country music.

He was ill .......... fever.

Look! That car is .............. ! Someone calls the fire brigade.

She was very surprised________ the grade she received.

Share these sweets .......... the five children and see that each one gets a fair share.

The children are really excited _____ their summer vacation.

I was disappointed ________ the grade I received on my last essay. 

She returned ____ China after spending much time abroad.

Plant and animal extinction leads _________ loss of biodiversity.

Don't put ____ until tomorrow what you can do today.

I don't think that I'm acquainted .......... him.

Mr. Johnson said he was ......... favor of doing the work right away.

She wanted to borrow some books__________ him but she was shy ______________ asking.

This style of architecture is typical ___ the Colonial period.

I’m good___________ English, but I’m bad____________ Mathematics.

The price of electricity is going up _____ August.

I'm terrified ..... breaking down on a motorway at night.