A:研制水溶剂涂料替代有机溶剂涂料
B:用可降解塑料生产包装盒或快餐盒
C:用反应:Cu+2H2SO4(浓) △ __ CuSO4+SO2↑+2H2O 制备硫酸铜
D:用反应:2CH2=CH2+O2 →Ag 制备环氧乙烷
I'd appreciate_____if you could come and help me once more and I always appreciate_____me with my English in the past.
A为数轴上表示-1的点,将A点沿数轴向左移动2个单位长度到B点,则B点所表示的数为( )
下面错误的算式是( )