straight-cut gear

例句：

1. 1. The new carhas a straight-cut gear that makesit easy to accelerate.
   这款新车配备了直齿轮，使得加速变得容易。
2. 2. The oldgearbox was difficult to work with,but the new one is much more straight-cut.
   旧的齿轮箱很难使用，但新的更直切。
3. 3. The engineerhad to replace the gearbox with astraight-cut design for better efficiency.
   工程师不得不用直切设计替换齿轮箱以提高效率。