Question

Tom had made up his mind to give it up, but on ____ second thought he determined to have ____ third try

1. A.
   a ; a
2. B.
   不填 ; a
3. C.
   不填; 不填
4. D.
   the ; a

Answer 1

B
本题考查冠词。on second thought固定结构，转念一想;a third time,又/再一次，无论序数词是几，都加a/an，句意：约翰本来打定主意放弃了，但转念一想，又决定再试一次。