A.divided

　　B.that divided

　　C.that divided it

　　D.that it divided

　　13)____ Earth's crust averages only 004 grams of the gold per ton, ……

　　A.Despite

　　B.Except

　　C.Although

　　D.Whether

　　14)In the process of v……,rubber is combined with sulfur, make it  ___ to heat and cold.

　　A.is resistant

　　B.to resist

　　C.resistant

　　D.resist

　　15)The presence in the US during the second world war of ___  European  su……  was decisive in the development of AE.

　　A.which many

　　B.many the

　　C.many are

　　D.many

　　16. Lake Michigan is the third (large) of the American Great Lakes and (the only) one (lying) wholly (within) the United States.

　　17. (Many) films (produced) in the United States (during) the 1930's were set in the American Civil War period and the years following (them.)

　　18. Children (who) form a positive self-concept are more assertive, optimistic, (confidence), and sociable (than those) who (do not).

　　19. Intaglio printing is the (oppose )of relief printing, since (the printing) is (done )form ink that (is below )the surface of the plate.

　　20. Form the outset, (the) formulation and teaching of technique figured (prominently) in the (development) of American modern (dancer).

　　21. Oil shales, (which may) furnish a (significantly) fraction of the world's future energy, vary in richness, (yielding) from four to fifty percent oil (by weight).

　　22. Government comprises the set of legal and political institutions (that) regulate the relationships (among) members of (a )society and between the society (or) outsiders.

　　23. Niagara Falls (is) not (only one) of (North America's greatest) tourist attractions but (also source) of hydroelectricity.

　　24. (Although) the beaver is a (powerful) swimmer, it has difficulty (moves) the logs and braches it (needs for) building and for food.

　　25. True cedars are (members) of the pine family and are 120 to 150 (feet tall), with (erect )cones and (bunches short), needlelike leaves.

　　26. Grandma Moses, the well-known American artist, began (to paint) at the age of 76 (when) she could (no long) do needlework because of arthritis.

　　27. (In) warm-blooded animals, body temperature (are) maintained within narrow (limits) regardless of the temperature of the animals' (surroundings).

　　28. Bret Harte, (which) best-known works describe life in California in the mid-1800's, (helped shape) the (literary) movement (called) local-color writing.

　　29. (With the) Democrats' adoption of (economic) radicalism in the 1890's, (and the) Republicans emerged as the (majority party) in the United States.

　　30. (The more) kinetic (energy in) the particles of (a material), the (hottest) the material is.

　　31.Weather forecasting was of vital (important) in the seafaring (and agricultural) lives (led by) the seventeenth-century European colonists (in what) is now the United States.

　　32.One (common) herb of the mint family is thyme, the (dried) leaves and flowering tops of which (is) used (to flavor) many different food.

　　33. Birds usually (have very) well-developed sense of (sight), and the optic lobes of (their brains) are (correspondingly) large.

　　34. Peter Cooper launched a number of (successful) commercial (enterprise), including the Canton Iron Works in Baltimore, (which produced) the first (commercially operated) North American steam locomotive.

　　35.Fainting (is caused) by stoppage of the blood supply to brain, due to (temporary) heart (fail) from shock, (weakness), or exhaustion.

　　36.The Fundamental physical (principle) of photography is that (light falling) on the grains (of certain) insoluble silver salts produces small, (invisibly) changes in the grains.

　　37. The oxygen of the atmosphere, (so) essential to (many of) forms of life, (represents) the accumulated product of over 3,500,000,000 years of photosynthesis (by) green plants.

　　38. Most of the world's energy ——(including) wind (and) water power and (all) fossil fuels ——(come) indirectly from the Sun.

　　39.(The wolf) was once the (most widely) distributed (kind of) mammal (on) the world.

　　40. Instruments that (measure) the passage (of time) have been in (exist) for (about) 4,000 year