2014年4月5日6时40分，云南省昭通市永善县（28.1°N，103.6°E）发生5.3级地震，震源深度13千米。关于本次地震的震源分布，说法正确的是(  ）

已知a、b为两个连续的整数，且$a<\sqrt{28}<b$，则a+b=____ 

      Yesterday when my son and I were eating dinner, I saw a policewoman walking past our house. A woman with a1look was following her.
      I opened the 2 , went out and asked if everything was OK. The policewoman said that the woman's3 had gone missing(失踪) an hour earlier. I said that we hadn't seen the girl, but wecould4.Iexplained to my son that we couldn't finish our5 right then. He said,” Be a kind person, Dad. "We got in our car and6 the girl all over the town. Along the way,a group of chil­dren were playing.  7they heard what had happened, they said they would help8 . They rode their bikes and joined us. 9 the little girl was found safe a few miles away. I was so 10to see many people help a stranger. It is a nice world.