山楂的性味是（）
A.辛、甘、酸，温
B.酸、苦，微温
C.酸、甘，微温
D.酸、苦，温
E.酸、苦、咸，温
参考答案：C
较易引起肺癌的尘肺是（）
A.矽肺
B.石棉肺
C.煤尘肺
D.铁矽肺
E.有机尘肺
--It’s clever _____ you to help me work out this difficult maths problem. Thanks.
--- You are welcome. Now it’s easier ______ you to understand it.
A．of; of
B．of; for
C．for; of
D．for; for
