21. Living in _______ ever increasingly fast-paced world, we are facing greater competition, so
we must take _______ advantage of every opportunity to develop.
A. an; the B. an; 不填 C. the; an D. the; 不填
22. I have a lot to say in relation ______ the affair.
A. with B. by C. to D. in
23. Ladies and gentlemen, please remain _______until the plane has come to a complete stop.
A. seated B. seating C. to seated D. seat