柔和的风0751
it is crucial to form the habit of exercising regularly.
it是形式主语，to form the habit of exercising regularly. 是真正主语
耗耗和妞妞
可以。it's crucial to do是由it做为形式主语的一种句型 ,其真正主语不是it,而是to do sth。 例句 It is crucial to measure inpatients' vital signs. 给病人测量生命体征是非常重要的。至关重要的 crucial;vital;
