As the visitor passes through the entrance, he or she encounters a dozen video screens, which show images of various animals exhibiting behavior typical of their species--a beaver building a dam, a spider constructing a web, and so on.
(the visitor; passes; through the entrance) (a spider; constructing; a web) (he or she; encounters; a dozen video screens, which show images of various animals) (a dozen video screens; show; images of various animals) (a beaver; building; a dam)
the visitor a spider he or she a dozen video screens a beaver
passes constructing encounters show building
through the entrance
a web
a dozen video screens, which show images of various animals
images of various animals
a dam