这台割草机使用的是二冲程发动机，噪音比较大但功率很高。

This lawnmower uses a ___two-stroke engine, which is noisy but very powerful.

这种小型发电机使用的是二冲程发动机，需要混合汽油和机油。

This portable generator uses a ___two-stroke engine that requires mixing gas with oil.