请选择ABC,T:L9k9YYou write_______e-mail on ________computer..f/i8S*X/b8L1q6a+S
A.a,an.f/i8S*X/b8L1q6a+S
B.an,a.f/i8S*X/b8L1q6a+S
C.an,/.f/i8S*X/b8L1q6a+S