You must ___________in this area unless you have messages about the casualty.(1.0)
A.keep radio silence B.keep radio silent C.keep radio be silent D.keep silent the radio正确答案B
You must ___________in this area unless you have messages about the casualty.(1.0)
A.keep radio silence B.keep radio silent C.keep radio be silent D.keep silent the radio正确答案B