78. An argument between the management and the staff resulted in the postponement of the Annual General Meeting. (PUT)

-> An argument between the management and staff put off the meeting. 

put off (phr. V) to delay or move an activity to a later time, or to stop or prevent someone from doing something: trì hoãn

80. The Prime Minister doesn't make a good impression on TV. (ACROSS)

->The Prime Minister doesn't come across on TV.

come across (phr. V): to give someone an impression: tạo ấn tượng

76. What has this experience taught you? 

->What conclusions have you drawn from this experience?

DRAW CONCLUSION FROM: to come to a conclusion after thinking about (what one has learned) rút ra kết luận

78. An argument between the management and staff put off the meeting. 

80. The Prime Minister doesn't come across on TV.

76. What conclusions have you drawn from this experience?

#chuchoctot

Xin hay nhất ạ!!!