估计$\sqrt{35}$的值是 （   ）

已知一元二次方程（m﹣1）x²+7mx+m²+3m﹣4=0有一个根为零，求m的值．

    John Clark was a postman. He was fond of dogs. However, when he was delivering（投递）letters, he found that 1dogs were his friends. One particular dog called2, who lived at No.108 Turner Road, was one of John's 3. Whenever John came near his 4house, Spot would lie in and 5out on John, barking（吠叫）and trying to 6his ankles.

    After a heavy snow,7was freezing that morning. The road was covered with8. John was afraid of 9 down, so he10his bike and walked with11steps. Unfortunately, John slipped on a patch of ice, which was opposite to No.108 Turner Road. Spot12this as John together with his bike made such a big noise.Spot jumped onto John's 13and tried to bite his neck.Quick as a flash, John,14hands were full of letters, bit15on the leg.

    John Clark said later, it was the 16thing I could do.I don't approve of（赞成）17to animals, but that dog18 had it coming. Since that day I've had no 19at No.108.Spot always hides round the 20of the house when he hears me coming.