Prepositions In, On, At

I was sitting .............. my desk.

• in

• on

• at

How many people are working ............. Microsoft?

• in

• on

• at

They once lived ................... number 12 South George’s Street.

• in

• on

• at

I know I left my wallet ............. the table.

• in

• on

• at

They live ............... the 15th floor!

• in

• on

• at

She works .................... an open-plan office.

• in

• on

• at

He found it difficult to concentrate .................. an office.

• in

• on

• at

Where will you be ................ New Year's Day?

• in

• on

• at

"I'm busy ....................... the moment, but I'll be free ................... the evening."

• in, in

• on, in

• at, in

• at, on