a down grade的用法和样例：
- The speed of a railway train is often much faster on a down grade.
- Their marriage is on the down grade.
- She's got a down on me; I don't know why.
- He made a down payment of $100,000 for the house.
- His career has been on the down grade.
- He makes a down payment of $100,000 for the house.
a down grade的相关资料：