50kg/m钢轨每米钢轨质量（）Kg。
A、60.64
B、74.414
C、44.653
D、51.514
参考答案：D
甲、乙、丙三人拿出同样多的钱共买回一筐苹果．甲和丙都比乙多拿了15千克苹果，并且分别给了乙30元，问：每千克苹果多少元？
_________ does your brother watch TV? Every Saturday and Sunday.[ ]
A. How many
B. How often
C. How much
D. How long
