问题：
[单选题]How would signalling language help in a presentation?
ATo help your audience to follow your trend of thought.
BTo advocate your opinion of the topic.
CTo clearly explain the visual part of a presentation.
[单选题]How would signalling language help in a presentation?
ATo help your audience to follow your trend of thought.
BTo advocate your opinion of the topic.
CTo clearly explain the visual part of a presentation.
