Thenewdiscovery_______beofgreatservicetomankind.
A、isboundtoA
be bound to：注定要，一定會。本題中主語是 The new discovery ，所以謂語動詞要用is。句意：這項新發現對于人類必定大有用處。
Ittookmeamonthtogetrid_______thecough.
Whenyou're_____acrisis,itoftenhelpstotalktosomeone.
Wateriscomposed_______hydrogenandoxygen.
Thefurnitureinherbedroomisquitedifferentfrom________inthelivingroom.
Aftermonthsofvoyage,Columbusarrivedin______laterprovedtobeanewcontinent.
