不规则需求往往给企业生产经营带来很多不便,所以我们应通过各种方式调节需求,使其尽量规则化。
参考答案:对
用方框中所给单词的适当形式填空,使短文通顺、正确、连贯(每个单词限用一次)。
How do you like friends? Should friends be the same or different? We 小题1: three students about the question last month. Here are the 小题2:.
Jeff Green thinks friends should be the same. He is a quiet and serious boy, and his best friend is quiet, too, So they enjoy 小题3: together. Another boy Huang Lei thinks friends should be different. Huang Lei is much 小题4: than his best friend Larry. So He often gets better grades than his friend. And They both like sports, however, Larry plays tennis 小题5: than Huang Lei. Mary Smith doesn’t mind if friends are the same or different. 小题6: best friend Carol is really kind and funny. Last year, Mary 小题7: her arm . Her friend Carol made her laugh and feel good. They can 小题8: everything.
They all think best friends are 小题9: important. Good friends should 小题10: each other.
25g大理石与盐酸完全反应可制得8.8 g的二氧化碳。(友情提示:大理石中的杂质不与盐酸反应)。
求:(1)碳酸钙中钙元素、氧元素的质量比是_________。
(2)大理石中碳酸钙的质量分数?