Why does a scientist need to use a special microscope to view how atoms are arranged in clear substance? A. because the substance is made up of clear atoms
B. because there are thousands of atoms in most substances
C. because the atoms are too small to see
D. because all atoms are invisible

What was piaget's explanation as to why preschool-age children in the preoperational stage make errors on tasks requiring conservation? a) preschool children's tendency toward centration prevents them from focusing on other relevant features of a situation b) preschool children have not yet developed numerical understanding; therefore, different amounts are meaningless c) preschool children's neural-visual network is not fully matured d) preschool children have not lived long enough and accrued enough experience to know the difference between quantities