Mrs. Green doesn't like sports. She has much work to do at home. Her mother is coming this afternoon and she goes to meet her. Near the school she looks at her watch. She has some time. So she goes into the school. Her son isn't in the classroom. She asks a boy and knows they're behind the school. She sees some boys playing there. Her son is there too. She watches them playing and soon she's angry. She takes her son to the wall. “Go home with me, Richard.” She says, "Don't play with them. I can buy a nice ball for you. Then you don't need to scramble for the ball."

有关俄罗斯自然条件的叙述，错误的是(    )