Answer :
1. solstice
- When the sun's center crosses the equator and day and night are of equal length everywhere.
2. estuary
- Broad mouth of a river into which the tide flows.
3. foci
- Plural of focus; central or meeting points.
4. sphere
- Globe; round or ball-shaped object.
5. glacier
- A large body of ice moving slowly down a slope.
6. equinox
- Time of year when the sun is farthest north or farthest south of the equator.
- When the sun's center crosses the equator and day and night are of equal length everywhere.
2. estuary
- Broad mouth of a river into which the tide flows.
3. foci
- Plural of focus; central or meeting points.
4. sphere
- Globe; round or ball-shaped object.
5. glacier
- A large body of ice moving slowly down a slope.
6. equinox
- Time of year when the sun is farthest north or farthest south of the equator.