2421If any part of the message are considered sufficiently impor
2023-12-01广-单-掌握-修正-002
2421If any part of the message are considered sufficiently important to need safeguarding, say: "（ ）" - followed by the corresponding part of the message.
A.Repeat
B.Say again
C.A and B
D.neither A nor B
正确答案是A
