某同学在用显微镜观察人体口腔上皮细胞临时装片是，选择下列哪组目镜和物镜的组合能在

缺词填空：根据短文内容和首字母提示,在下文空格处填入适当的词使短文完整。(每空一词)

       Let me tell you something about Spring Festival in China. Every year people c  1   it all over China.

Usually it is in January or February. It is the most important f   2   in China. So before it c   3  , every family c   4    their houses and buy many things. And they often m_ 5   a special kind of food c   6    dumplings.

It means 'come together'. People always buy new clothes for their children and children also buy presents

for their p   7_. On the eve of the Spring Festival, family members meet for a big d   8   . Then they watch TV until midnight. They e   9    singing, dancing and playing cards. At twelve, people give e   10    other

the best wishes for the coming year.

欧拉运动微分方程在每点的数学描述是（）。

A、流入的质量流量等于流出的质量流量

B、单位质量力等于加速度

C、能量不随时间而改变

D、服从牛顿第二定律

基建工程供方首次进入公司建筑市场时，向基建工程供方管理部门提交有效证件包括哪些？

国际饲料分类法中，第六类饲料是（）。

A、能量饲料

B、蛋白质饲料

C、矿物质饲料

D、添加剂饲料

火力发电厂的汽水系统主要由（）、（）和凝结器、加热器、除氧器等设备组成。