extend the credit balance

例句：

1. 1.The train will extend for 30 minutes.
   火车将延长30分钟。
2. 2.We need to extend our reach to the remote areas.
   我们需要扩大我们的活动范围到偏远地区。
3. 3. The company plans to extend its operations into new markets.
   公司计划将其业务扩展到新的市场。