中国自20世纪60年代开始进行海洋油气资源的自营勘探和开发。（）
Studentsshould_____theirowninterestsaswellasdotheirschoolwork.
WhenwasthereferendumonQuebec'sfuturestatusheldinCanada?
Thereistheappreciationofthesalienthistoricaltruth________theagingofadvancedsocietieshasbeenasuddenchange
Howmanypartsdoesascienceandtechnologypaperconsistof?Whatarethey?
