句子主语常为人, 找出主语Helen,情态动词should置于主语之后,且其后需用动词原形,brush,根据搭配,可知词组为:brush her teeth,剩下时间状语为:in the morning. 故本题答案为:Helen should brush her teeth in the morning.
Take some medicine and drink some warm water.
句子缺乏人称,故句子为祈使句,根据动词take, 与drink各自搭配,可知take some medicine, drink some warm water, 连词and连接并列结构。可知本题答案为:Take some medicine and drink some warm water.