选择题：Vocal variety are the changes in a speaker’s rate, pitch, and volume that give the voice interest and expressiveness.

It is important to put ethical principles into practice during my preparation of my speech.这是一个关于口语与演讲的相关问题，下面我们来看答案是什么，It is important to put ethical principles into practice during my preparation of my speech.A.正确B.错误正确答案：正确

（）How to make our speech a success?这是一个关于口语与演讲的相关问题，下面我们来看答案是什么，（）How to make our speech a success?A.choose an attractive topicB.practice a lotC.good deliveryD.be audience-centered正确答案：choose an attractive topic；practice a lot；good delivery；be

When using PowerPoint, it’s not necessary to limit the bullet points and texts, or limit animations.这是一个关于口语与演讲的相关问题，下面我们来看答案是什么，When using PowerPoint, it’s not necessary to limit the bullet points and texts, or limit animations.A.正确B.错误正确答案：错误

When referring to both females and males, it is better to use the word “man”.这是一个关于口语与演讲的相关问题，下面我们来看答案是什么，When referring to both females and males, it is better to use the word “man”.A.正确B.错误正确答案：错误

促成煤变质作用发生的最主要因素是什么？这是一个关于因素 温度 煤化学的相关问题，下面我们来看答案是什么，促成煤变质作用发生的最主要因素是什么？A.时间（）B.温度C.压力D.位置正确答案：温度