помогите пожалуйста сделать 4 и 5 задания

4.
Are you a student? Yes, I am
Is your friend a student? Yes, she is.
How old is your friend? My friend is 20 years old.
What is her name? Her name is Kate.
Where is she now? She is at university.
Were you a student last year? Yes, I was.
Was your friend a student last year? Yes, she was.
Will you be an economist? Yes, I will be.
What will your friend be? My friend will be a lawyer.
Where will you be tomorrow? I will be at home tomorrow.

5.
Economics is a science and subject.
This is a famous Russian economist.
They were familiar with Keynes's work.
Were they his students?
As far as I know they weren't his students.
I didn't know answer this question .