Then moment _________ Mary will always remember is _________ Mr．Black gave her a lot of valuable advice on how to improve her writing．
A．when; thatB．that; thatC．that; whenD．when; where
The problem was very difficult to handle．We worked it out，__________ ．
A．too B．yet C．although 
D．though
—Can I pay the bill by check?
—Sorry，sir．But it's the management rules of our hotel that payment be made in cash．
A．shall B．need C．will D．can
Helen was much kinder to her youngest child than she was to the others， ，of course，made the others jealous．
A．who B．that C．which D．what
is known to us is that tobacco contains nicotine and other harmful products，so you should give up smoking．
A．As B．It C．What D．Which
——Which of the two souvenirs do you like better?
—— blue one．of course．I think it's really most instructive one．
A．A；the B．The；the C．The；a D．A；a
