4.4. Most large cities had public libraries supported by taxation or private philanthropy, ________.
(A) and sometimes either one (B)sometimes by one of them
(C)and sometimes one way of the other (D)sometimes by both
5.5. A busy computer keeps careful track of ________.
(A) metals costing of a million molars (B)the millions of dollar worthing metals
(C)the millions of dollar worth of metals (D)the million’s worth metals
15.15. It is the high humidity that makes London winters so chilly, _________.
(A) not that its temperatures are being low (B) not lowness of temperature
(C) since low temperatures are not as present (D) not the low temperatures
21.21. Many modern skyscrapers, though visually pleasing, they have heating and cooling systems that require closed windows and consequently waste energy.
(A)visually pleasing (B) they have (C)closed (D)waste