14. The discovery that electricity could produce magnetism __________ in 1820 by the Danish physicist, Hans Christian Oerested. a. by accident b. was an accident c. was made by accident d. by accident was

5. Food of animal origin generally supply greater amounts of iron to the diet than __________ a. are foods of plant origin b. foods of plant origins c. do foods of plant origin d. plant origin foods

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6. __________ energy for growth or repair, a plant must carry out photosynthesis. a. To obtain b. It obtains c. It is obtaining d. Obtaining

7. Nicotine, __________ found in tobacco, is named after the French diplomat Jean Nicot. a. it is a chemical compound b. is a chemical compound c. a chemical compound d. chemical compound is

10. __________ an organism to become a fossil. a. Rarely b. It is rare c. Rare is d. It is rare for

11. Among sea horses, __________ carries and hatches the eggs in a special breeding pouch. a. it is the male which b. the male it c. it is the male d. the male who

2. __________ more than 2,000 minerals are known, nearly all rocks are formed from seven mineral groups. a. Although b. However c. Despite d. Since A

15. Digital systems work first by changing quantity and then __________ into strips of numbers. a. convert the measurements b. the measurements convert c. to convert the measurements d. converting the measurements

3. Alexander Graham Bell worked with deaf students before __________ the first telephone in 1876. a. designed b. was designed c. to design d. designing

4. An enzyme works by coming in contact with a particular substance, __________ with it, and changing it. a. combines b. combining c. it combines d. to combine

12. __________ will be increasingly used as a source of petrochemicals when oil begins to run out. a. No matter coal b. No doubt coal c. If coal d. That coal