The boys were happily making a snowman,
问题:
The boys were happily making a snowman, _________ with cold.
A.their faces red
B.their faces were red
C.their faces to be red
D.their faces turned red
The boys were happily making a snowman, _________ with cold.
A.their faces red
B.their faces were red
C.their faces to be red
D.their faces turned red