题目内容：

填介词或副词They're treining _ the boat race
Bears can walk _ like man.It's very funny.
You can only buy one of this kind of cheap pen _ a time.
( )If you have nothing important to do,you can walk _ and enjoy yourself.
A.through B.across C.around D.upright

优质解答

Bears can walk ____upright___ like man.It's very funny.You can only buy one of this kind of cheap pen ___at____ a time.( C )If you have nothing important to do,you can walk _ and enjoy yourself.A.thro...