．No one knows exactly when our ancestors started talking，but new evidence suggests _______might have happened a long time ago．
#16908
A
which
B
what
C
it
D
they
推荐题目
Mr Brown has three children, one of whom is a child of six, twins of twelve.
#14817
A
another
B
the other
C
the others
D
other
Here are two pairs of shoes, ______ you may choose.
#15995
A
both of them
B
either of them
C
any of which
D
either of which
-----Can I ask you a few straightforward questions about yourself?------No problem. I like______ when people are open and direct.
#15637
A
that
B
this
C
it
D
them
—All the volunteers were very tired, but of them took a rest.—They were busy looking for the missing people.
#57326
A
neither
B
all
C
both
D
none