— The doctor is busy ________ his work.
#48117
A
at
B
for
C
with
D
on
推荐题目
The young men walked ______ the forest and came to a big river at last.
#50208
A
on
B
over
C
through
D
across
My friend Jimmy was born_______1998_____ a winter morning _______December.
#51019
A
in; on; ／
B
in; in; ／
C
in; in; of
D
in; on; of