1. Pennsylvania ranks high among the states population _____ many areas are sparsely settled.

2. Some metropolitan newspapers would make sizable volumes _____ in book form.

3. Perfectly matched pearls, strung into a necklace, _____ a far higher price than the same pearls sold individually.

4. Organic chemistry has made many new products _____ .

5. _____ to space travelers is high acceleration or deceleration forces.

6. _____ stereophonic phonograph records, two recordings are made of the same musical performance.

7. _____ executive and administrative authority in the United States government rests with a President who is elected for a four-year term.

8. The slide rule uses sliding scales with marks _____ numbers and their logarithms.

9. The position of the larynx, or voice box, in the neck determines _____ , swallows, and vocalizes.

10. _____ reaches the cells of the body, it is oxidized, or slowly burned.

11. _____ all data into electronic pulses.

12. Lunar eclipses occur each time the Earth blocks the Sun’s light from the Moon _____ the Moon’s full phase.

13. The ancient Hopewell people of North America probably cultivated corn and _____ crops, but hunting and gathering were still of critical importance in their economy.

14. Scientists think _____ helps some tree to conserve water in the winter.

15. With affection and humor, poet Phyllis McGinley _____ of ordinary life.