Onlywhenyouhaveobtainedsufficientdata________cometoasoundconclusion.
过渡时期的总路线的主体是________。
Wewerebusy________(get)thingsreadyforthetrialproductionwhenhephonedus.
Ipreferthisdiagram________thatone.
EachyearintheUnitedStates,manyblackteenagers_______ofschool,eitherbecausetheycannotkeepuportheyhavetoworktosupporttheirfamily.
