—Must I give the pen to the manager ?
—No, you may give it to________you think is on duty in the office ．
A．whomever B．no matter who
C．whoever D．who
Look! The dictionary, ________cover is red, is a birthday gift given by Tom．
A．which B．whose C．its D．where
_______environmental damage is done, it takes many years for the ecosystem to recover．
A．Even if B．If only C．While D．Once
Every possible means _______to prevent the air pollution, but the sky is still not clear．
A．are being used B．have been used
C．has been used D．had been used
______ surprised the family most was ________the girl played basketball very well．
A．That; that B．That; what C．What; that D．What; what
I have to see the doctor because I________a lot lately．
A．cough B．coughed
C．have been coughing D．had coughed
