使用医疗器械可能或者已经引起严重健康危害的，应实施（）
A.一级召回
B.二级召回
C.三级召回
D.无需召回
参考答案：A
对对联。
上联：读好书乐趣无穷
下联：_____________________________
Rick is ________ young ________ go to school. Don't you think so? [ ]
A. too; to
B. so; that
C. such; that
D. as; to
