____ of the land in that district ____ covered with trees and grass.

A．One half; are

B．Two seventh; is

C．A quarter; is

D．Two thirds; are

大规模研究试验显示，近年上市的环氧化酶-2抑制剂中，可增加心血管不良反应风险的药品是

A．酮康唑
B．洛伐他汀
C．罗非昔布
D．利血平
E．阿昔洛韦