D. Eat lots of fresh shellfish. This is how a person with lactose intolerance can obtain dietary calcium.
Weight that is below the desirable body weight is under-weight :]
Spirituality involves a personal belief or meaning and purpose to life.
(U wrote this wrong as well.)
Not really. I suffer from extreme social anxiety so I am the opposite, being anxious around strangers and more comfortable around people I know. Some people may find being around people who don't know them well less anxiety-inducing because they don't feel forced to open up or show their sensitive side. Just my theory, so don't take my word if you think something else :)