At times, worrying is a normal________ to a difficult event or situation—a loved one being_______ in an accident, for example.
24.You didn't believe John won the first prize at the speech competition, ______?
23.I had reached a point in my career _____ I needed to decide which way to go.
22.Here are some new computer programs _____ for home buildings.
21._______ sweet and fresh, this kind of food is so popular with local people and the tourists.
20.Always read the label ______ you wash your clothes.