Questions

Schwann cells or neurolemmocytes are the cells in the peripheral nervous system that form the myelin sheath around a neuron's axon.

Henry's Law tells that the solubility of a gas is directly proportional to the partial pressure of the gas above the solvent. Hence under high pressure, more gas is dissolved.

Also that Henry's Law involves a constant which is temperature-dependent. Under high temperatures, less gas is dissolved whereas under low temperatures, more gas is dissolved.

For Example ::  

You can think of a can of soda. The contents are under pressure and if you shake the can before opening, the soda fizzes out all over as you open it. So the higher the pressure, the more gas or more CO2 can be dissolved in the drink.

Eliminate choices 1 and 2. Now focus on the temperature. Soda goes flat (loses carbonation or gas) as it warms up. Soda is usually served cold because more of the carbonation or CO2 stays in the drink when the soda is cold.

Hence, in high pressure and low temperature conditions gases are most soluble in water.

Now a days, printers we are using are called as laser printers. The speed of a laser printer is measured in PPM i.e, Pages Per Minute. 

Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to define a differentially charged image.

Compared to inkjet printers which use ink for printing laser printers are more expensive as they use toner which lasts for long.