Basic terminology $2$: Select all of the following statements that are true.

With respect to inputs for Machine Learning systems, the terms feature and instance can be used interchangeably.

Semi$-$structured data can be found, for example, in e$-$mails.

Dimensionality reduction is a supervised Machine Learning technique.

Semi$-$supervised Learning always relies on semi$-$structured data.

In supervised Machine Learning, the two main phases for model improvement are training and testing.