(D) their electrical charges draw them away from the earth
27. The word "random" in line 7 is closest in meaning to (A) unpredictable (B) perplexing (C) independentI (D) abnormal
28.What can be inferred about 0drops of water larger than 0.008 inch in diameter? (A) They never occur. (B) They are not affected by the force of gravity. (C) In still air they would fall to earth. (D) In moving air they fall at a speed of thirty -two miles per hour.
29 How much bigger is a rain 0drop than a cloud 0droplet ? (A) 200 times bigger (B) 1,000 times bigger (C) 100,000 times bigger (D) l,000,000 times bigger
30. In this passage, what does the term "coalescence" refer to (A) The gathering of small clouds to form larger clouds (B) The growth of 0droplets (C) The effect of gravity on precipitation (D) The movement of dust particles in the sunlight
People appear to be born to compute. The numerical skill of children develop so early and so inexorably that it is easy to imagine an internal clock of mathematical maturity guiding their growth. Not long after learning to walk and talk, they can set the table with impressive accuracy---one plate, one knife, one spoon, one fork, for each of the five chairs. Soon they are capable of noting that they have placed five knives, spoons, and forks on the table and, a hit later, that this amounts to fifteen pieces of silverware. Having thus mastered addition, they move on to subtraction. It seems almost reasonable to expect that if a child were secluded on a desert island at birth and retrieved seven years later, he or she could enter a second-grade mathematics class without any serious problems of intellectual adjustment.
Of course, the truth is not so simple. This century, the work of cognitive psychologists has illuminated the subtle froms of daily learning on which interllectual progress depends. Children