10年前王锋的年龄是他女儿的7倍，15年后王锋的年龄是她女儿的2倍，问王锋女儿的年龄是多少( )
A．10
B．15
C．30
D．45
参考答案：B
—I hear _______ students in your class like hiking on weekends.
—Yes, you are right. Exercise is good for us.[ ]
A. quite a bit
B. a quite bit
C. a few quite
D. quite a few
2岁女孩，已确诊为重型β地中海贫血。
其基因缺陷位于（）
A.X染色体
B.11号染色体
C.13号染色体
D.15号染色体
E.16号染色体
