Until the middle of the 20th century, doctors sometimes suggested that
people smoke in order to reduce stress. since then, doctors have been asking
patients who smoke to quit.
what caused this change?

How does buring fossil fuels impact does carbon cycle? what large impact does this have on the envirnment?

Hydrilla (hydrilla verticillata) is an invasive aquatic plant and one of the most serious aquatic pests in florida. hydrilla has already been introduced to hundreds of bodies of water throughout florida, hydrilla is difficult to control because it grows rapidly and survives in many different water depths and conditions. hydrilla • describe how hydrilla affects native plant and animal species. include both a biotic and an abiotic limiting factor. • suggest one biotic and one abiotic recommendation that could slow the spread of hydrilla

Which of these parts of the membrane large moecules pass through it ?