Explanation:
As the Earth moves around the sun during a year, the northern half of the Earth is tilted towards the sun in the summer, making daytime longer than night. In winter, this reverses; the earth tilts away from the sun and nighttime becomes longer
The sideways and downward movement of the edge of a plate of the earths crust into the mantle beneath another plate
Yes, it can - HBr is its chemical formula.
If you had other options though, then the one which wouldn't be a valid chemical formula is aluminum (III) chloride, because, since it only has one charge (+3), it is unnecessary to state it as III.