Who invented the vacuum tube in 1906?

"After my presentation, my audience will know how to make the perfect chocolate chip cookie," is what type of a statement?

A. general purpose B. central idea C. specific purpose D. descriptive purpose

What does it mean when a speaker "reads" an audience during a speech?

A. The speaker is using cue cards to read a previously written speech. B. The speaker is paying attention to cues that reveal listeners' emotional state. C. The speaker is telling the audience members' fortunes. D. The speaker is reading profiles that were written about audience members.