I’m sorry I _______ your lecture yesterday, but I _____ busy recently. A missed, have been B miss, am C had missed, was D have missed, had been
He stayed there for quite a long time, during ________ time he learned much spoken English.
The man showed us so heavy a stone ________ no man can lift.
Some pictures of the river brought the days back to the old ________ they swam in it.
Is this research center ________ you visited the modern equipment last year?
The humans are destroying nature day by day, ________ of course, will cause severe punishment from it sooner or later.