Withonelegbrokeninthatcaraccident,hecannotevenwalk,____run.
ProfessorJohnsonissaid_____somesignificantadvanceinhisresearchinthepastyears.
Modern____perhapscausesmoreproblemsthanitsolves.
Thismissileisdesignedsothatonce_____nothingcanbedonetoretrieveit.
Evenifhisletter（）tomorrow，it（）toolatetodoanything.
