They are called neurotranismitter
<span>In a long day, a person goes through different daily activities, completes different tasks, goes to work, runs errands, and others. With all the activities that a person goes through, sleeping is required in order to relax and replenish energy. The word that completes the sentence is relaxation.</span><span />
Water can pass throught the cell membrane because, the cell membrane has little holes in the membrane allowing water to go through