The flight was delayed for two hours owing to _____ reasons. A: adaptive B: alterative C: extensive D: technical

Which of the following inflammations is alterative inflammation?() A: Nose mucositis in early stage of cold B: Pseudomembranous inflammation C: Villous core D: epidemic encephalitis

According to Mr. Hall, what is opportunity cost（） A: It is the relationship between two kinds of goods or services that customers may want to buy. B: It is people’s choice of goods and services at similar prices. C: It is the relative value of goods to buyers compared to the value of alterative goods and services on which they may want to spend that same amount of money.