问题
单项选择题
The emergency communication set’s transmitter should not be tested except when()by a public radio inspector.
A.inspecting
B.inspected
C.inspects
D.having inspected
答案
参考答案:B
The emergency communication set’s transmitter should not be tested except when()by a public radio inspector.
A.inspecting
B.inspected
C.inspects
D.having inspected
参考答案:B