肝炎病人怕吃油腻食物的原因是( )
A:唾液分泌过少
B:胆汁分泌过少
C:胃液分泌过少
D:肠液分泌过少
If something is _______, it is known about by only a few people.
草履虫在阳光下向暗处移动,在光线弱时向光源处移动,这一现象说明生物具有( )