这里a=2,b=1,
则x1x2=ca=-1,
故选A.
—He is eager to try something he has never tried before.
—Oh, I see. That’s _______ he’s different from others.
A.when
B.where
C.how
D.what
颅内压增高引起最严重的后果是()
A.血管源性水肿
B.胃肠功能紊乱
C.Cushing反应
D.脑疝
E.细胞毒性脑水肿