例句與造句

1. The brakes failed as a result of the collision and the tram began to roll backwards down the step gradient of Raymond Donoghue guided the remaining passengers to the front of the vehicle as it was rolling backwards, and warned motorists by continuing to ring the tram's bells and desperately trying to operate the emergency hand brakes to no avail.
2. It's difficult to find step gradient in a sentence. 用step gradient造句挺難的