I _________ busy with my homework today.
1.am
2.was
3.is being
4.have been
John ___________ to the countryside since Easter.
1.hasn't been
2.has been
3.didn't be
4.wasn't
They ____________ infomed me that I will be working next week. *
1.have just informing
2.have just informed
3.just informed
4.were just informing