填空题

What is the very small animal that has eight legs, eats small insects, and sometimes bites people It is the spider.
Spiders are not insects; they are arachnids. Insects have three pairs of legs and three body parts. Arachnids have four pairs of legs but only two body parts. Spiders have two to four pairs of eyes. They can see extremely well.
When a spider bits an insect, it doesn’t kill the insect immediately. Instead, a special poison passes through its fangs and this poison paralyzes the body of the unlucky insect.
Most spiders make their own homes. They do this with a special substance produced by their bodies. In the corners of some rooms it is possible to find a spider’s web where the spider is waiting for its next dinner guest.
Unlike an insect, a spider has four (46) , two (47) and two to four pairs of eyes which make it (48) . It kills an insect with (49) , and builds its home with (50) from its body.