函数f(x)=x3-3x2+1是减函数的区间为[ ]
A.(2,+∞)
B.(-∞,2)
C.(-∞,0)
D.(0,2)
D
Does the wolf live ________ the forest or ________ the desert? [ ]
A. in, in
B. in, on
C. on, in
D. on, on
积液发生在睾丸、精索鞘膜内的是()
A.睾丸鞘膜积液
B.精索鞘膜积液
C.婴儿型鞘膜积液
D.交通性鞘膜积液
E.附睾囊肿