【Couldyouhelpmebuysomedrinks?Sorry,Ican't.____,Idon'thavemoney.a:Butb:andc:ord:正确答案是A,但不知道为什么.请各位大虾指教!】

　　Couldyouhelpmebuysomedrinks?Sorry,Ican't.____,Idon'thavemoney.

　　a:But

　　b:and

　　c:or

　　d:

　　正确答案是A,但不知道为什么.请各位大虾指教!