苯酮酸尿症是由于先天性缺乏
A．苯丙氨酸羟化酶
B．苯丙氨酸转氨酶
C．酪氨酸羟化酶
D．酪氨酸转氨酸
E．酪氨酸酶
参考答案：A
_______in a famous university is what most students wish for. [ ]
A. To educate
B. Educated
C. Being educated
D. Educating
黑种人头发的横切面呈（）.
A.圆形
B.扁圆形
C.长形
D.椭圆形
