朗读下面短文，体会、领悟加黑连接词引导的是什么从句，在从句中作什么成分。
What worries my classmate, Mary, a lot these days①is that she puts on too much weight and is frequently ill②.She has some doubts whether she eats too much fast food high in fat or sugar③.Also, with the College Entrance Examination approaching, she becomes more stressful and she couldn't sleep well these days.Maybe this is also the cause that she becomes fatter these days④， she thinks. How she becomes slimmer and healthier⑤has been her main task. So she wants to consult some experts and gain some instructions. But where she could get better suggestions and who will give her better advice⑥also puzzle her. It is her parents' suggestion that she should consult Professor Wang in Zhongshan Hospital⑦.Professor Wang suggests that she keep a balanced diet first⑧. She should eat vegetables and fruit high in fiber, vitamin and protein. What's more, if she wants to lose weight, she had better take regular exercise more than half an hour a day. Mary asked Professor Wang when she should take exercise⑨.Professor Wang advised her to take exercise at 5 o'clock in the afternoon because she will have more time to do sports.Thanks to Professor Wang, Mary has become much healthier now.
[用法体悟]
①为主语从句。What(＝The thing that)在从句中作主语。
②为表语从句。从句本身意思完整，不缺任何句子成分。
③为同位语从句。补充说明doubt的具体内容，因doubt (疑惑)的意思本身是不确定的，故由whether引导。
④为同位语从句。说明the cause的具体内容。
⑤为主语从句。表示“如何”变得苗条些和更健康些，故用how引导，how在从句中作方式状语。
⑥为主语从句。表示去“哪里”咨询、向“谁”咨询，故分别用where, who引导。
⑦为同位语从句。说明suggestion的具体内容，从句内容完整，不缺任何句子成分。
⑧为宾语从句。从句内容完整，不缺句子成分。
⑨为宾语从句。when在从句中作时间状语。
