【C15】A．tillB．whenC．whereD．although

【C16】A．whetherB．whenC．whereD．why

A．WhetherB．WhenC．IfD．Although

【C19】______A．whichB．whenC．thatD．where

【C16】A．BecauseB．WhenC．BeforeD．Although

【C3】A．whatB．whenC．thatD．where

【C9】A．tillB．whenC．whereD．although