Which is more highly regioselective the addition of hcl
tomethylenecyclohexane or to 1-methylcyclohexene?

Addition to methylenecyclohexane is more highly regioselective.

Explanation:

This is because there is a greater difference in the activation energies leading to a primary and tertiary carbocation than in the activation energies leading to a secondary and tertiary carbocation.

introduction of a drug directly into the respiratory tract is a form of inhalation administration.

explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.