781.I called the airline to _____ my flight reservation a week before I left for Canada.

A.obtain

B.admit

C.confirm

D.appoint

782.If your race car isn't insured, you may _____ losing everything when it hits something solid.

A.delay

B.deny

C.avoid

D.risk

781.答案是C;

obtain获得，得到；admit承认，公认;confirm证实，巩固，确认;appoint委派，任命。

782.答案是D;

delay耽搁，延误;deny否认;avoid避免:冒险。此处risk doing sth.冒险干某事。