New words：

course /kɔːrs/ n. 课程；讲座

Sample Sentences：

She is planning to take a computer course.

The course will help me look after the children.

Students have a free choice of courses in their final year.

New words：

optional [ˈɒpʃənl] adj. 可选择的；选修的；随意的

Sample Sentences：

The goods are optional, but only one.

Some courses in college are required while others are optional.

Is English an optional lesson, or does everyone have to learn it?

course /kɔːrs/ n. 课程

New words：

option [ˈɒpʃn] n.选项；选择；选择权；可选择的事物

Sample Sentences：

I had no option but to ask him to leave.

We need to consider all available options before making a decision.

The government has two options, to reduce spending or to increase taxes