以下语句正确的是 （100kcb
A) dim a as new XXXXXXXXXt.webclient
XXXXwnloadfile("XXXXXXXXXXXXX',"XXXXm")
B) dim a as XXXXXXXXXt.webclient
dim b as bitmap
b=XXXXwnloaddata("XXXXXXXXXXXXX")
C) dim a as new XXXXXXXXXt.webclient
dim b as string
b=XXXXwnloadstring("XXXXXXXXXXXXX")
D) dim a as XXXXXXXXXt.webclient
dim b as long = "123"
a.uploaddata("XXXXXXXXXXXXX",b)
