A、生后4-6个月
B、8个月-1岁
C、1-15岁
D、2-25岁
Mrs.Smithlockedboththefrontandthebackdoorsbeforeshewenttobed______thatsomeonemightstealintothehouseatnight.
A、so
B、forfear
C、unless
D、oncondition
_______thatthescientistwillgiveusatalknextmonth?
A、Istrue
B、Isittrue
C、It’strue
D、It’struly
Thereistheappreciationofthesalienthistoricaltruth________theagingofadvancedsocietieshasbeenasuddenchange
A、Which
B、what
C、that
D、how
重写句子：Fossilfuelsarenon-renewable.Weneedtofindalternativeenergysources.(compoundsentence)