1. The younger you are, _______ it is to learn. a. easier b. you are easier c. the easier d. the easy 2. _______ porpoises and dolphins, whales are mammals. a. As b. Also c. Like d. When 3. The Romans used central heating systems very much like_______. a. those of today b. to day's do c. those they do d. the systems which are now. 4. The higher one rises in the atmosphere, _______ the temperature generally becomes. a. colder than b. the colder than c. the colder d. is colder 5. Nerve cells, or neurons, _______ in the human body. a. the most complex cells are b. are the most complex cells c. most complex the cell are d. most are the complex cells 6. The United States spends more money on advertising_______ country in the world. a. other b. other than c. than any other d. while other 7. The rooms in the front_______ noisier than those in the back. a. are more b. are little c. are very d. are much 8. A microscope can reveal vastly_______ detail than is visible to the naked eye. a. than b. than more c. more than d. more 9. _______plants, which manufacture their own food, animals obtain nourishment by acquiring and digesting their food. a. Unlike b. Different c. Whereas a. As much 10. Of all the candidates, Peter is probably_______ a. the less qualified b. the qualified less c. the most little qualified d. the least qualified 11. These two girls_______ that I can't tell them apart. a. are so like b. are so alike c. are too alike d. alike enough 12. This house is_______ the others we've seen. a. father more expensive than b. far more expensive than c. far most expensive d. further more expensive 13. Apart from Pluto, the outer planets_______ the inner planets and are made mainly of lighter materials such as hydrogen and helium. a. are larger than b. are the largest c. large than d. are large 14. This is_______ man of all I've been known. a. best b. better c. good d. the best 15. _______ we finish the project, _______ we can start the next one. a. The soonest/ the sooner b. The sooner/ the most soon c. The sooner/ the sooner d. The soonest/ the soonest 16. That child behaves_______ of all a. the most carelessly b. the more carelessly c. more carelessly than d. as carelessly 17. It is_______ that I have read it twice. a. such an interesting book b. so interesting a book c. too interesting a book d. a or b 18. For many children, nothing seems so exciting_______ their first airplane ride. a. so does b. as c. same d. is 19. A baby might show fear of an unfamiliar adult, _______ he is likely t smile and reach our to another infant. a. if b. whenever c. so that d. whereas 20. The deep oceans contain some of the_______ of all living creatures. a. strangest b. strange c. as strange as d. stranger