More than three-quarters of the children we interviewed said they’re sometimes afraid to be home alone. If you decide your child is (67) enough to be home alone before or (68) school, you should make sure your house is (69) and teach your child to (70) 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" (71) "someone you don’t know comes (72) the door." The best home security is (73) . Every home should have smoke detectors, but consider also installing a burglar-alarm system. Leaving a radio (74) during the day makes a home sound (75) . 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. (76) it with a neighbor instead. (77) your child is home alone, the phone is a vital (78) . A parent or designated (指定的) adult should always be available by (79) . Children should know where to find (80) numbers, and how to (81) the phone and take a message without letting an unknown caller (82) no one else is home. You might (83) a telephone-answering machine. Your child (84) then be able to pick up the receiver only when he heard a (85) voice. If you help your child understand the precautions you’ve taken, he will feel more (86) about staying home.

A. When
B. Where
C. However
D. Which