They would have to `sing for their supper' during the exhausting official round of duties.他们不得不在那些耗人精力的官方手续的办理过程中进行疏通。They would have to 'sing for their supper' during the exhausting official round of duties.他们不得不在那些耗人精力的官方手续的办理过程中进行疏通。We had to stop the pump and unblock it.我们只能把水泵关掉进行疏通。