There is two way to select other parts :

1. To select one other part,
   Hold down a control key on the keyboard and click on the part you want to add.
2. To select all the part between the last selection and another part,
   Hold down the control key and the shift key and click on the other part all the part will be selected.

   The following exemple will illustrate this :
   We start with the state of the fig 17.

fig 17

We want to add another part "Preacher #004 - [23 of 28] - Preahcer_1995_#004_22.jpg(3/3)"
To do this hold down the Control key on the keyboard and put the mouse cursor on the subject "Preacher #004 - [23 of 28] - Preahcer_1995_#004_22.jpg(3/3)" then left click the result will be shown in fig 18.

fig 18

We want to add all the part between "Preacher #004 - [23 of 28] - Preahcer_1995_#004_22.jpg(3/3)" and "Preacher #004 - [23 of 28] - Preahcer_1995_#004_21.jpg(2/3)"
To do this hold down the Control key and shift key on the keyboard and put the mouse cursor on the subject "Preacher #004 - [23 of 28] - Preahcer_1995_#004_21.jpg(3/3)" then left click the result will be shown in fig 19.

fig 19