问题
选择题
Tom had made up his mind to give it up, but on ____ second thought he determined to have ____ third try.
A．a ; a
B．不填 ; a
C．不填; 不填
D．the ; a
答案
答案：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。