It should be formal! (answer b).
The hint in the question is that the city major will attend the ceremony- this tells you that the ceremony will have a more representative, formal character, and will not be an internal celebration among people who know each other (this would make it informal or semi-formal).
A scientist that would be most likely to study peking man is an archaeologist.
Trade is when two or more people exchange items such as food , money , books and etc...
When our country = America ( USA ) trades goods such as money , or food and medical supplies to other countries ( Nations ) to help them and in return we might get more supporters or better Technology.
I really hope that this helps you out a lot.
Using the mnemonic. Hope this helps, have a BLESSED day! :-)
