①When is New Year's Day?
____
②Mother's Day is in May.
③We have a sports meet.
④We have a maths test in April.
These pictures show the of life. Who them?
常压下羰基化法精炼镍的原理为：Ni（s）+4CO（g）⇌Ni（CO）4（g）．230℃时，该反应的平衡常数K=2×10﹣5．已知：Ni（CO）4的沸点为42.2℃，固体杂质不参与反应．
第一阶段：将粗镍与CO反应转化成气态Ni（CO）4；
第二阶段：将第一阶段反应后的气体分离出来，加热至230℃制得高纯镍．
下列判断正确的是（ ）
—Could you tell me the________ of making such tasty cakes?
—Well, I just follow the directions in the cookbook.
地球上的纬线，不正确叙述是（ ）
