单项选择题
It's desired that she ______ to teach us at least twice a week.
单项选择题 ______ , you must show your ticket to go into the cinema.
单项选择题 Our children and grandchildren will ______ if we don't look after our planet.
单项选择题 Anyone, rich or poor, old or young, sick or ______ , can pick up a hobby.