Answer:
The combined new sentence uses a compound object.
Step-by-step explanation:
Let's underline what the two original sentences have in common:
1. Antarctica has a thick ice cover.
2. Antarctica has the highest average elevation of all continents.
The two sentences have the same subject and the same verb. Therefore, when we combine them, the new sentence will have a single subject and a single verb. On the other hand, they have different objects after their verbs. That means the combined sentence will incorporate the two objects, making one compound object. To do that, we will need the conjunction "and":
- Antarctica has a thick ice cover and the highest average elevation of all the continents.