21.This experiment turned out to be ____ failure, but as we know, success often comes after _____ failure.
A. a; a B. 不填；不填 C. a; 不填 D. 不填; a
22.The good thing about children is that they ______ very easily to new environments.
A. adapt B. appeal C. attach D. apply
23. ---- Was his suggestion accepted at the meeting last night?
---- Partly. Some are _______ it, while some are against it.
A. in charge of B. in case of C. in favour of D. in response to
