补充词语。
( )( )协力 众志( )( ) 博( )众( )
( )学( )问 小( )大( ) ( )( )倒置
同 心 成 城 采 长 勤 好 题 做 轻 重
It was three o'clock _______ he came back from work.[ ]
A. since
B. that
C. before
D. when
Joan had a total of $16.50 in her coin bank. How many quarters does she have (1) The bank contains only quarters and dimes. (2) There were 81 coins in the bank.