科学家发现人与黑猩猩的细胞色素C差异最小，与马的差异则大一些，而与果蝇、向日葵的差异更大．科学家研究的方法是（　　）

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依次填入下列句子横线处的词语，最恰当的一项是（ ）

①是的，或许所有的人都早已习惯于污浊了，但我们仍然固执地制造不被      的清新。

②拾一片树叶，细数      的纹理，那都是命运神秘的手相。

③从繁华、喧嚣的市中心来到这山清水秀的避暑胜地，我们感到      。

④今年我校参展的科技小制作有2000多种，形状各异，色彩缤纷，令人      。

阅读下面一则学校海报，选择正确答案。

SCHOOL EVENTS

OPEN DAY（开放日）：

AUGUST 16th, 2012 9:00 ~ 12:00 a.m.

All parents can come to our school, have a cup of coffee, and meet our teachers and other parents.

Parents can go to the classrooms of 12 ~ 15 years old, have a talk with the principal (校长), have a look at the clubs and ask any questions.

All requirements（要求）for a happy school are welcome.

Lunchtime: 11:30 ~ 12:00 a.m.

Please go to Room 305 for lunch.

All parents are welcome. Please contact (联系) us.

Contact: Melodie Lezar, the principal

TEL: 021- 4615998

E-mail: disapark@ telkoms.a.net

School: Goodwin Middle School

— What does your mother do, Li Jie?

— She is a (an)        . She teaches (教书) in a high school.

30＋40=____　　70－40=____　　20＋70=____　　 80－10=____