помогите плиз прошу 'ммммммммм номер 276 и 277

276.
1. The Earth isn't very big, is it?
2. How many seas are there on the earth?
3. There are a lot of countries on the earth aren't  there?
4.What is the longest river on the earth?
5. What are the oldest mountains on the earth?

277.
Здесь нужны специальные вопросы. То есть требуются вопросительные слова.
1.Where does she often see him?
2. Where were they playing?
3. Where did they have house?