题目内容：
根据以下内容，回答题。One British school is finding that allowing children to listen to music or even to have the TV on while studying is helping improve grades. 21 your teenager starts a family quarrel by sitting in an armchair listening to music while doing his homework, why not 22 a simple experiment? Rather than taking the heavy handed(严厉的) line of ordering him to his bedroom to get on with it 23 , let him do the homework the 24 he wants. You might well find that his essay is more sparkling(有文采的) than 25 he's done before.
According to the research of Millfield prep school, around 20% of youngsters 26 best with background music, 10% excel (突出) when allowed to break up their work with short walks around the room while up to 80% can concentrate(集中注意力) 27 if allowed to fiddle (用手拨弄) with a small object.
The research has advised the school to adopt (采取) a complete 28 approach (措施), analyzing pupils to discover which learning style 29 them best--then letting them do their work listening to music or 30 lying down. Doubtful parents at first regarded the move as a layabout's(懒散闲荡的人) deed but many are now applying it at 31 where children are also allowed to do their work 32 the television on.
"I 33 to work on the floor with music on low," admits Susan, 13, a day-girl(走读 女生). "At first my parents thought I was skiving(逃避), but my 34 persuaded them to look at my homework and when they saw it was OK, they 35 "
（ ） A．Next time
B．Then
C．Before long
D．In case
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