一个宇航员在地球上的体重是84千克，是他在月球上体重的6倍．他在月球上的体重是多少千克？（用方程解）

Tinea is a skin infection caused by certain fungi. A significant fraction of the people who contract tinea have outbreaks of its symptoms again and again. This proves that, for each of these individuals, the original case of tinea was, in fact, never completely cured.
The argument above assumes that a person who has outbreaks of tinea symptoms again and again

A．can never be completely cured of tinea.

B．does not understand what causes tinea.

C．did not get medical treatment for the original case of tinea.

D．did not take steps to avoid contracting tinea.

E．(E) has not been repeatedly infected with tinea.