—Have you ever seen two leaves that are exactly the same?—Never. Leaves differ ____ each other ____ size and shape.
Whatever happens, Tom, ________ drugs.
If a healthy environment is gone, ________ everything that our life depends on.
—Under no circumstances ________ the door to the Data Centre unlocked. —I promise I'll be more careful in future.
The drug used to treat this disease causes bad side effects, some of which ________ deadly.
.No sooner ________ down on bed ________ the telephone rang.