根据题意得:x(x+1)=0且x≠0,
解得x=-1.
故选C.
(2013·济南模拟)I found Jane________at the desk,________her homework carefully.
A.seated;doing
B.sitting;does
C.be seated;does
D.sit;do
消化性溃疡()
A.呕血伴规律性腹痛
B.强烈呕吐后继而呕血
C.呕血伴腹痛、黄疸、寒战与高热
D.呕血伴全身皮肤出血
E.鲜血样大便