具有杀虫功效的药物是
A.白及B.仙鹤草C.棕榈炭D.血余炭E.炮姜
参考答案:B
The more one is _______ the English-speaking environment, the better he or she will learn the language.
A.filled in
B.exposed to
C.caught on
D.kept up
50岁以上中、老年人便血,应考虑是()
A.肠息肉
B.直肠癌
C.肠套叠
D.小肠结核
E.粘连性肠梗阻