问题
选择题
_____ about the safety of her son, John's mother looked upset. [ ]
A. Concerning
B. Concerned
C. To concern
D. Concern
答案
答案：B
搜题请搜索小程序“爱下问搜题”
_____ about the safety of her son, John's mother looked upset. [ ]
A. Concerning
B. Concerned
C. To concern
D. Concern
答案：B