问题详情

Complete the summary below.
Choose NO MORE THAN TWO WORDS from the text for each answer.
Write your answers in boxes 10-13 on your answer sheet.
Freebie marketing is not permitted by law for either illegal or legal (10) products. This type of promotion of goods such as tobacco and alcohol is not considered worth the (11) and has consequently been outlawed.
"Tying" is also prohibited. This is when the sale of an attractive product is (12) on the purchase of another. It tends to occur when the seller takes advantage of a natural monopoly and is generally considered to be 13 (13) .
(10)请帮忙给出正确答案和分析，谢谢！