-7的倒数是 ；
分析：此题根据倒数的含义解答，乘积为1的两个数互为倒数，所以-7的倒数为1÷（-7）．
解：-7的倒数为：1÷（-7）=．
故答案为：．
单句改错。
( )1. This is his the best book. ________
A B C D
( )2. He is taller than any boy in his class. ________
( )3. Which do you like best, this one or that one? ________
( )4. Mike is very cleverer than Jack .________
( ) 5. Kate draws best of her class. ________
“七十-73半”从概念上讲是指运用多种持刀方法，修剃整个面部的细毛，不得少于七十-73半。
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