1. It’s quite an informal gathering; you needn’t _______ for it.
A．dress down B．dress up
C．dress D．dress on
2.［2012大庆模拟］The largest collection ever found in England was one of about 200, 000 silver coins,_____ over 600 years old.
A. all of which B. all of it
C. all of that D. all of them
