Only through constant practice can the ability of using a foreign language be _______. 
#71692
A
earned
B
acquired
C
gained
D
achieved
推荐题目
30. Please write a notice for the students and ______ .
#80469
A
put it up  
B
put up it 
C
put it on  
D
put on it
It must have taken a long time to _______ all the facts of these old books.
#66913
A
dig out
B
take out
C
break up
D
take apart