Older people should ______ politely.

(单选题)A number of high buildings have arisen ______ there was noth (单选题)Can you tell the ______ difference between the words “requir (单选题)The monkeys of the circus always give very funny and interes (单选题)Stanley has a strong sense of responsibility; as soon as he (单选题)The cleaner was on the spot and saw what really happened, so (单选题)I shall never forget those years ______ I lived on the farm (单选题)Ordinary soap, ______ correctly, can deal with bacteria effe (单选题)It was with the help of the local guide ______ the mountain (单选题)—Is there anything else I can do for you, Jeff?—No. Thanks. (单选题)Both Prof. Li and Dr. Huang are ______.