What is the structural formula of functional group of ether?

Classify the following alcohols as $1^{\mathrm{o}}/2^{\mathrm{o}}/3^{\mathrm{o}}$ and allylic/benzylic.

${\mathrm{H}}_2\mathrm{C}=\mathrm{CH}-{\mathrm{CH}}_2-\mathrm{OH}$, 

What are the electronic effects exerted by $-{\mathrm{OCH}}_3$ and $-\mathrm{Cl}$? Predict the acid strength of  and  relative
to parent phenol .

Which of the following represents the increasing order of boiling points of $\left(1\right),\left(2\right)$ and $\left(3\right)$?

$\left(1\right)$ ${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\mathrm{OH}$

$\left(2\right)$ ${\left({\mathrm{CH}}_3\right)}_2\mathrm{CH}-\mathrm{O}-{\mathrm{CH}}_3$

$\left(3\right)$ ${\left({\mathrm{CH}}_3\right)}_3\mathrm{COH}$

Which is the best reagent for carrying out the following conversion?