Some sentence,I talked many time and I don’t use body movement to presentation. It make the content is insipid. The audience are bored.In the pronunciation,I pronounced some word incorrect such as ch and sh,f and v,and the and this. Both two consonants have similar voice. When I say
wrong consonant,the word and meaning will change. It make the audience understand not meaning. Therefore,I should say slowly and pronounce the consonant is clear.