Some snakes have special sensory organs that detect the infrared region of the electromagnetic spectrum. Compared with human vision, these snakes can sense electromagnetic waves that have 1 a lower frequency and a shorter wavelength. 2 a higher frequency and a longer wavelength. 3 a lower frequency and a longer wavelength. 4 a higher frequency and a shorter wavelength.

Compared with human vision, these snakes can sense electromagnetic waves that have:

3. a lower frequency and a longer wavelength.

Explanation:

Human eyes are not able to detect the infrared region of the electromagnetic spectrum. We can experience it as heat when, for instance, we get close to a hot object. The snakes mentioned in the passage, however, have special sensory organs that can detect infrared, which means they sense waves that have a lower frequency and a longer wavelength than the ones visible to us. Let's compare infrared to what is detectable by human eyes:

Visible:wavelength: 400 nm – 700 nm; frequency: 790 THz – 430 THz.

Infrared:  wavelength: 700 nm – 1 mm; frequency: 430 THz – 300 GHz.

The longer the wavelength, the lower the frequency.

the correct answer is d. in john paston's letter written friday, 14, 1476, he expresses his fear that he may have to go to war.

indeed, although the black death was ravaging europe, the pastons were relatively safe from it due to their social status as they were part of the landed gentry. it is clear that the vast majority of the victims of the pandemic were the poor. the reason why he is weary of having to go to war is because at the particular time england was also devastated by the war of the roses and paston, being a courtesan was inevitably involved.