同一个字符串。
短暂性动词 延续性动词
borrow(借) keep(借/保留很长时间)
join the army(参军) be in the army(在军队里)
die → be dead;
leave→ be away(from) ;
finish / end→ be over;
begin / start → be on;
come here → be here;
come back→ be back;
marry → be married;
fall asleep / get to sleep → be asleep;
return → be back ;
get up→be up;
put on →wear ;
become →be;
catch a cold → have a cold。