— It's _____ eraser, and _____ eraser is Tom's.

①No matter what hard the project is, I will finish it on time.

②They were extreme sad at the thought of their missing dog.

③I was about to lock the door while the telephone rang.

④Burying in his study, he didn't know that all the others had left.

⑤It's so nice weather that I'd like to take a walk.

⑥Mr. Smith insisted that the thief put into prison.

⑦The number of teenagers injured in the earthquake is frightened.

⑧Smoking can do damage for your health.

⑨I find the man is very difficult to get along.

⑩My father bought a new bike for me which price added up to more than 1000 Yuan.

我国历史上少数帝王曾妄想“长生不老”，盲目服用“仙丹”，其结果大多英年早逝。当今一些生物学家在研究小白鼠实验时，发现了“返老还童”的生命现象，这或许给人们延缓衰老提供了新的思路。以下是该课题的实验设计方案：

一 实验准备：

1）选取健康且生命特征相同的18月龄白鼠和3月龄白鼠若干只备用。

2）分别抽取3月龄和18月龄白鼠的血液若干毫升，分装到不同的瓶中备用。

二 实验设计：

三 实验探究