A、He can offer many technical details to them. B、He can give them more than 3 facts to remember. C、He can make his speech longer

How can a speaker successfully hold an audience’s attention during his speech? What is the secret?
    First, find out about the audience and what they need to know. Plan what you’re going to say and say it clearly and concisely. (33) A good speaker uses various signals to help hold the audience’s attention and make the information clear. One type of signal is to introduce a list with a phrase like There are three things we have to consider. The speaker then says what the three things are and talks about each one at the required level of detail.
    Another signaling technique is to give a link between parts of the presentation. Say where one part of the talk finishes and another starts. For example, a well organized presentation usually contains different parts and progression from one part to the next must be clear, with phrases like that’s all I want to say about the development of the product. Now let’s turn to the actual marketing plan. This technique is very helpful to the audience, especially those who are mainly interested in one part only.     Another type of signaling is sequencing of information. This usually follows a logical order, perhaps based on time. Key words in sequencing information are first, then, and so on.
    (34) Still another technique which helps to emphasize key points is careful repetition. Examples are As I’ve already said, there is no alternative but to increase production by 100 per cent...
    A final point concerns timing and quantity of information. (35) Psychologists have suggested that concentration is reduced after about twenty minutes without a break or a change in activity. Furthermore, audience should not overburdened with technical details or given too many facts to remember. It is claimed that to ask people to remember more than three things in a five minutes’ talk is too much.
    Every speaker needs to think about exactly how much information of a particular type a specific audience is likely to absorb and to plan accordingly.
33．How can a good speaker hold the audience’s attention?
34.How can a good speaker emphasize the key points in his activity?
35.How can a speaker lengthen the audience’s attention?