Does selectively permeable membranes allow only certain materials to pass through them

the language dates from the contacts of arabian traders with the inhabitants of the east coast of africa over many centuries. under arab influence, swahili originated as a lingua franca used by several closely related bantu-speaking tribal groups.

radioactive dating, also known as  radioisotope dating  is a process that in  estimating the approximate  age  of  rocks. these data can be analyzed from  the studies dealing with the  decay of the radioactive elements that are present in these rocks. in nature, there are a few types of materials or atoms which are quite unstable and they spontaneously decay or breakdown to form other kinds of atoms.