Mywalletisnowheretobefound.I_____itwhenIwasonthebus.
A、mustdrop
B、shouldhavedropped
C、haddropped
D、musthavedropped
A、eitherRussiannor
B、neitherRussianor
C、noRussiannor
D、neitherRussiannor
A、疏通呼吸道
B、正确输氧
C、维持正常体温
D、以上都是
Themeeting_____nextweekwillbeofgreatimportance.
A、tobeheld
B、held
C、holding
D、isheld
重写句子：Theteacherreturnedthehomework.Theteachernoticedtheerror.(complexsentence)