21.（单选题）You must sign to accept the terms and conditions as the application will only be processed with the applicant’s signature.

31.（单选题）Everyone should _______ his/her duty to help the company.

30.（单选题）Some software programs have a very powerful __________ .

29.（单选题）Many fashions are _________ on the website.

28.（单选题）Nowadays, Internet _________ is a rapidly developing industry in China.

27.（单选题）It ______ true that sport is about competing, not winning.

26.（单选题）This river is badly ______ by life wastes.

25.（单选题）Some______ baby food is contaminated, thus harmful to health.

24.（单选题）It______ to my pleasure to see you here today.

23.（单选题）Computers have greatly increased ______ in business offices.

22.（单选题）You ______ to be here an hour ago!