Some reptiles, like snakes, have olfactory receptors (smell)

on their tongues
on the roof of their mouths
on their skin
at the tip of their tails

I think the correct answer would be the second option. Some reptiles, like snakes, have olfactory receptors (smell) on the roof of their mouths. As we can observe, snakes usually flick their tongues. This action is made so that they would collect substances from the ground or the air. Their tounges do not have the receptors for smell and taste rather it is located in the roof of the mouth or the vomeronasal. As the tongue goes inside the mouth of the snake, it is being received by the receptors in the mouth and would transmit a number of signals to the brain. The tongue simply deposit the substances that was collected onto the mouth.

Covalent bond is the correct answer

Schools are being forced to embrace computers. unlike their "digital immigrant" teachers, these students are "digital natives", born into a world where technology is an integral part of everyday life. almost every student has access to a multitude of computers, laptops and tablet devices. it would be crazy to assume an assignment would  notbe written on computer in this day and age.many schools now have a 1-to-1 computer policy, and many districts and states in the united states have mandated computers or ipads across the state for every student,  including los angeles, the second largest school district in the country.but the thing is, when they tried it in la, it wasn't the success they hoped for. that's because the tablets weren't used as much as they expected. rather, it appeared there was a gap between the digital native's love of technology and their use of it in the classroom.this conflicted relationship with computers is also underscored by much of the literature on education. it is also highlighted in professional development and conferences such as  edutech.