函数y=lg(x2-1)的定义域是______.
函数y=lg(x2-1)的定义域是:
x2-1>0,
解得x>1,或x<-1.
故答案为:(-∞,-1)∪(1,+∞).
The teacher gave back his homework, so he _ do it again. [ ]
A. must
B. had to
C. needed
D. might
企业制度以()为基础和核心。
A.生产制度
B.责任制度
C.人事制度
D.产权制度