Johnsonwas________unknownbeforerunningforthepresidency.
D
A 显然，明显地 B 外表上，直观地 C 垂直地，直立地 D 实际上，事实上
_______ is a fact that English is being accepted as an international language.
Iwaswritingareportlastnight;________Iwouldnothavestayeduplate.
Theoldcouplehavebeenmarriedfor40yearsandneveronce_______witheachother.
Ifyouarewalkingawayfromaclocktower，youwillhearthetickingoftheclockfadetoapoint________itcannotbeheard.
Thisisanimportantproblem_______toofewsocialscientistshaveresearched.