设Ω为开集,£。∈n,z(t):以一l’,1<p<。。.证明,27(£)一{xn(t)}在t0弱可导的充要条件是:
(1)存在正的常数δ与M,使得当0<|h|≤δ时有≤M
(2)每个分量函数xn(t)都在t0可导.
听力原文:I wouldn't give that rumor about Jim any credibility.
(27)
A.I wouldn't buy the ridiculous story about Jim.
B.I don't think the rumor is incredible.
C.The rumor about Jim is believable.
D.I wouldn't give Jim any credibility because of the rumor.
听力原文:Why don't we write a memo to all employees?
(A) We didn't receive it.
(B) That's a good idea.
(C) They are in the Accounting Department.
(27)
A.
B.
C.