More than three-quarters of the children we interviewed said they're sometimes afraid to be home alone. If you decide your child is【C1】______enough to be home alone before or【C2】______school, you should make sure your house is【C3】______and teach your child to【C4】______various situations. Make a game of your instructions. Have your child answer questions beginning with 'What would you do if' and ending with phrases like 'you lost your key'【C5】______'someone you don't know comes【C6】______the door.' The best home security is【C7】______. Every home should have smoke detectors, but consider also installing a burglar-alarm system. Leaving a radio【C8】______during the day makes a home sound【C9】______. Besides, as one child said, 'It's horrifying walking into a quiet house.' Don't leave an extra key in obvious hiding places, such as under the doormat.【C10】______it with a neighbor instead.【C11】______your child is home alone, the phone is a vital【C12】______. A parent or designated(指定的)adult should always be available by【C13】______. Children should know where to find【C14】______numbers, and how to【C15】______the phone and take a message without letting an unknown caller【C16】______no one else is home. You might【C17】______a telephone-answering machine. Your child【C18】______then be able to pick up the receiver only when he heard a【C19】______voice. If you help your child understand the precautions you've taken, he will feel more【C20】______about staying home.【C1】A．matureB．braveC．oldD．strong