英语翻译：undermanned
Whatarethekeyfeaturesofaresearchpaper?
重写句子：Hockeyisasportwhichispopularinmanycountriesaroundtheworld.(simplesentence)
Thevehiclewastravelingatspeeds________90milesperhour.
重写句子：Fossilfuelsarenon-renewable.Weneedtofindalternativeenergysources.(compoundsentence)
