"The lecturer was a tall thin man with white hair." "Then it _______Dr.Fell because he is short and fat.It_____Dr.Jones;he is thin."
A、can'tbe/mustbe
B、mightn'thavebeen/couldhavebeen
C、mustbe/can'tbe
D、can'thavebeen/musthavebeen
Mysisterwasn'tinParislastmonth,soyou_____herthere.
A、mightnothaveseen
B、can'thaveseen
C、mustnothaveseen
D、shouldn'thaveseen
As is known to us all,the age_____children can go to school is seven.
Nora:Howlonghasthisbookshopbeeninbusiness?
Michel:______1982.
A、After
B、In
C、From
D、Since
The time has come _____ we make extensive use of nuclear energy.
A、When
B、while
C、as
D、since