英语翻译1.a hobby often develops into a serious study of their h

英语翻译
1.a hobby often develops into a serious study of their habits.
2.attacting number of birds continually to the same spot can be harmful to them,particularly species that pick food from the ground contaminated by the droppings of other birds.
3.if you start a local increase of birds,be prepared to do what may be required to eliminate hazards to those you want to befried.
2中attacting 应该是attracting.3中的befried应该是befriend.