Tostudyaforeignlanguage,__________.
A、agooddictionaryshouldbebought
B、buyingagooddictionaryisnecessary
C、youshouldbuyagooddictionary
D、itisnecessarythatyouwillbuyagooddictionary
I'msorryIforgottowrite;Ihadsomuchelse________mymind.
A、over
B、for
C、on
D、about
Wemust______thattheexperimentiscontrolledasrigidlyaspossible.
A、assure
B、secure
C、ensure
D、issue
Whenworkersareorganizedintradeunions,employersfindithardtolaythem________.
A、off
B、side
C、out
D、down
Asyoulikepopmusic,__________Ilikeliterature.
A、so
B、therefore
C、as
D、thus