Terrible!!! sight does not work on snipers (IGI 2: Covert Strike)

In short, I figured out a fig knows where to a healthy house on a Chinese island, I liked the igruha very much and here it’s such a zadagnich that I cannot do without a sniper, I was perverted in every way ... but I can’t spin the
wheel on the mouse. ..
maybe I'm doing something wrong?

How can you aim with a sniper?

IGI 2 Covert Strike version 1.0