1 The party last last night was __success,we sang and danced until it came to__ end at twelve.

1 The party last last night was __success,we sang and danced until it came to__ end at twelve.
A a;the B a;an 为什么是A,不是 B
2 In order not to be disturbed ,Ispend three hours__ in my study
A locking B locked 为什么不是A,是B