Indicate the true statements concerning the functional impression taking technique:

1) functional impression should be taken in the open mouth;
2) functional impression may be taken both in the open and closed mouth;
3) in the open mouth, the movements performed by the patient may be enhanced by the operator;
4) passive functional impression is not indicated;
5) impression material should be setting quite fast taking into account the very common gag reflex in patients;
6) impression material for functional impressions should have quite a long plasticity time;
7) all the impression materials available on the market may be used in this technique;
8) ZnOEu impression pastes and silicone impression materials of various consistency are indicated in taking functional impressions;
9) two-step impression taking technique is advised, with preliminary functional tray border molding and then taking the impression as a whole; 10) one-step impression taking technique is preferred, with the use of proper silicone impression materials.
The correct answer is: