Definition: In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. Your answer should be chosen from the given text, and should not contain other words.
Input: Sofi:  How many senses do worms have ?
Ian: They have _ two _ . Smell and touch . Why ?
Sofi: So ... they live without any ability to see or even know about light , right ? The notion of light to them is unimaginable .
Ian: Yeah .
Sofi: But we humans ... we know that light exists . All around them ... right on top of them ... they can not sense it . But with a little mutation , they do . Right ?
Ian: Correct .
Sofi: So ... Doctor Eye ... perhaps some humans , rare humans ... have mutated to have another sense . A spirit sense . And can perceive a world that is right on top of us ... everywhere . Just like the light on these worms .

senses