疽毒内陷的病理是：（）
A.正胜邪实
B.正胜邪衰
C.正虚邪胜
D.正虚邪衰
E.正邪相持
参考答案：C
已知数列{an}的前n项和Sn=n2-9n，则其通项an= 若它的第k项满足5<ak<8，则k=
It was _____ of Jack to turn off the radio when I was sleeping in the bedroom.
A．considerable
B．considerate
C．disturbing
D．sensible
