A) the exercises were very difficult, nobody (know) what to do with them. 1)had known 2)had knew 3)known 4)knew b)everybody (leave) the house by the time i came home. 1)leaved 2)left 3)had left 4)had leaved

A) The exercises were very difficult, nobody knew what to do with them. (4)
B) Everybody had left the house by the time I came home. (3)