To remove magnesium oxide layer from the ribbon which may prevent or slow down the burning of magnesium ribbon.
The answer to your question is gravity. you are welcome. :-D
Answer:
a. Heterogeneous
b. Homogeneous
c. Homogeneous
d. Heterogeneous
e. Heterogeneous
Explanation:
A heterogeneous mixture is a mixture in which you can see multiple different ingredients in, for example vegetable soup, tea with ice and lemon slices, or fruit salad.
A homogeneous mixture is a mixture in which you can only see one thing, for example tea, seawater, or milk.
D. Is a fly shot effective in preventing the flu?
Answer A touches on the topics of economics and industrial feasibility of the flu shot.
B is more of an ethical / situational question.
C is a social question.
D is the only question which focuses on the science of microbiology and medicine.