thErE wAs no nEws From kissingEr whilE hE wAs in BEijing, ChiEFly BECAusE ______ .
A．his trip hAD to BE kEpt sECrEt
B．prEsiDEnt yAhyA DiD not go with kissingEr
C．CommuniCAtion BEtwEEn BEijing AnD islAmABAD wAs DiFFiCult
D．thE nEgotiAtion(谈判) wAs not suCCEssFul