The word sonar(声纳) is formed by means of_________.

A good conclusion of a presentation usually consists of_________.

To pay the debts which are due in July, Russia will have to pay out a sum of_________.

The act of marking off the goals and achieving them individually will give you a greater sense of_________. (accomplish)

The value of a business owner's time is an example of_________. A: a fixed cost B: an opportunity cost C: total revenue D: an explicit cost

In a presentation, a good conclusion usually consists of_________. A: a brief summaryof main points B: a short conclusion if necessary C: showing gratitude to the audience for their presence D: leading up to a question and answer session