Exploring the city with trolley cars and many hills. This city is San Francisco, CA.
Trolley cars or cable cars were introduced in 1873 to enable locals to contend with many hills the city is built on. Now, tourists ride the cable cars and will be given a tour of the city.
B) One swims freely and the other often lives attached to a hard surface.
Answer:
limiting factors
Explanation:
The ecological optimum represents the value of the factors within the ecological valence at which the life processes of a species take place best. The upper and lower limits of an ecological valence are its maximum and minimum. Beyond these limits, physiological processes are interrupted and death occurs.
Solutes dissolved in water on either side of the cell membrane will tend to diffuse down their concentration gradients, but because most substances cannot pass freely through the lipid bilayer of the cell membrane, their movement is restricted to protein channels and specialized transport mechanisms in the membrane
They are connecting bone to bone forming joints<span />
