采用开采保护层时，一般下保护层比上保护层影响范围大
正确
暂无解析
Arrivingatthebusstop,_____waitingthere.
Hegaveusagood____ofhisexperience.
_____ifIhadarrivedyesterdaywithoutlettingyouknowbeforehand.
Ifyou_____insuchahurry,you_____sugarintothesauceinsteadofsalt.
Rockmusicusually____theyoungpeopleinmostcountries.
