How are ferns, gymnosperms, and angiosperms alike?

They all are vascular plants.

Explanation:

Gymnosperms are the plants which have naked seeds and ovules. They do not produce flowers. The angiosperms are the flowering plants. The ovules are enclosed inside the female flower. They produce seeds. The ferns are the seedless plants, they reproduce via spores. Gymnosperms, angiosperms and ferns share common characteristics like they have vascular system that is tissues like xylem and phloem help in conduction of water and minerals from the soil. The plant body is differentiated into root, stem and leaves. They all have photosynthetic pigments in them.

altitude, density, pressure

air gets less dense the higher the altitude and also the air pressure is less as altitude rises.

the answer is true.