Not select two Items

Hi Expert,   I am doing the crash course but I don"t know why I shall "not select" those two items in step 3 below. Are there any specific reasons?   Setting Up a Mapping Now that you’ve told Mendix what your data looks like, you’ll have to map it to data structures in Mendix. This is done via an Import Mapping. Right-click the Import folder and select Import Mapping from the Add Other sub menu. Can you guess the naming convention here? The name should be ImM_Department_Employee. Select the JSON Structure from the previous assignment. Copy the selection from the image below. Carefully note the two items which are not selected.
1 answers

You just might be misreading line 3. It does not tell you to "not select" the two items, rather it just tells you to "note the two items", so note them, and understand why they are not selected.