题目内容：

.The largest collection ever found in England was one of about 2000,000 silver pennies,all of _____ over 600 years old.
A.which
B.it
C.that
D.them
选D,望解析

优质解答

空格说指的应该是silver pennies,故只能用复数,就排除了B.C
all of _____ over 600 years old.如果这个句子前面是句号,则要用which,逗号的话就用them