题目内容：

It's every parent's worst nightmare. 1.. Now scientists say they have found a better way to wake up sleeping youngsters. Researchers in the US have discovered that playing a child a recording of their mother's voice is about three times more likely to wake them than a traditional alarm. Moreover, they can escape more quickly.

Dr Gary Smith, a co－author of the research from the Nationwide Children's hospital in Ohio and his colleagues report how they compared the effects of four different smoke alarms on 176 children aged between 5 and 12 years old.2.. While one alarm featured a high－pitched beep, the other three featured the voice of the child's mother calling either the child's name, giving instructions such as: “Wake up! Leave the room！”， or both. Each child slept in a lab－based room that resembled a real bedroom, and was shown how to escape from the room before they went to bed. They each experienced all four alarms—the order of which was chosen randomly.

3.. About 90% of children woke for a vocal alarm compared with just over 53% for the traditional alarm. In addition, the children shook off their sleep faster, with a median(中位数) value of two seconds for the voice alarm compared with more than two and a half minutes for the traditional alarm.4.．

Prof Niamh Nic Daéid, director of the Leverhulme Research Centre at the University of Dundee, said the research supported by her team found a human voice combined with a low－frequency pulsing tone was far more effective in waking children than a traditional high－pitched alarm.5.， which might have made them more responsive to an alarm, while more work was needed to explore whether other familiar sounds, such as a dog barking, might also prove effective in waking up children.

A. But she noted that the latest study involved children sleeping in a location other than their own bedroom

B. But she said it was important to look at developing better alarms

C. None of them had hearing difficulties or were taking any medication that affected their sleep

D. The results show that voice alarms appear to be more effective than high－pitched beeps

E. What's more, it does so faster and is linked to a quicker escape

F. There's a fire in the house; the alarms are beeping, but the children are in deep sleep

G. Similarly, escape times were longer in the cases of the beeping alarms