As I remember, last year, we held the following types of training classes, such as: vegetable planting, fruit planting, pig breeding, agricultural machinery management and so on. As I remember, last year, we held the following types of training classes: vegetable planting, fruit planting, pig breeding, agricultural machinery management and so on.

Alternative: "We held different types of training classes, such as..."

Each classourse usually ranges from 5 to 25 days. Each course usually ranges from 5 to 25 days.

A class is generally a short period of time, such as an hour or a day. A course is a longer time frame consisting of multiple classes.

The class should includeconsist of one-third of theoretical teaching and two - -thirds of practical teaching. The class should consist of one-third theoretical teaching and two-thirds practical teaching.