I keep medicines on the top shelf, out of the children’s       .

 In China, shaking hands with each other is a common________ when people meet for the first time.

— Mum, hurry up. We’ll be late.— I will be through in a minute. Have a little ________.

Future will be a marvelous world of artificial ______----- robots might have their emotions and we human beings might have robots as friends．

Finding information in today’s world is easy．The_______is how you can tell if the information you get is useful or not。