“补钙新观念，吸收是关键。”小丽的妈妈一直给她喂奶粉，可是医生说小丽患佝偻病，原因在于喂奶粉时没有喂 

根据达尔文进化论的观点，人类起源于（    ）

根据句意和汉语注释，写出单词的正确形式。
（1）Our English teacher has offered us some useful ____  (建议). I think it will help us a lot in our English study.
（2）Here are two ____ (音乐会) tickets for you.
（3）Daniel ____ (不愿)  to accept my books ,which made me very sad.
（4）____ (比较) this new TV set with the old one, you will see which is better.