脾肿大最常见的原因是（）
A.门脉高压
B.白血病
C.淀粉样变性
D.类肉瘤病
E.脾外伤
参考答案：A
The house, which is large and is surrounded by trees and flowers, is what she longs for ．
A．directly
B．extremely
C．skillfully
D．exactly
请写出一个字母x的二次根式，且x的取值范围x＜1．并说明其正确性．
