新东方优美背诵短文50篇 Unit50:CellsandTemperature
Cells cannot remain alive outside certain limits of temperature and much narrower limits mark the boundaries of effective functioning. Enzyme systems of mammals and birds are most efficient only within a narrow range around 37C;a departure of a few
新东方优美背诵短文50篇 Unit28:Changing Roles of Public Educa
28 Changing Roles of Public Education One of the most important social developments that helped to make possible a shift in thinking about the role of public education was the effect of the baby boom of the 1950's and 1960's on the schools. In the 19
新东方优美背诵短文50篇 unit24 Piano
24 Piano The ancestry of the piano can be traced to the early keyboard instruments of the fifteenth and sixteenth centuries -- the spinet, the dulcimer, and the virginal. In the seventeenth century the organ, the clavichord, and the harpsichord becam
新东方优美背诵短文50篇 unit13 Skyscrapers and Environment
13 Skyscrapers and Environment In the late 1960's, many people in North America turned their attention to environmental problems, and new steel-and-glass skyscrapers were widely criticized. Ecologists pointed out that a cluster of tall buildings in
新东方优美短文背诵50篇 unit11 Museums
11 Museums From Boston to Los Angeles, from New York City to Chicago to Dallas, museums are either planning, building, or wrapping up wholesale expansion programs. These programs already have radically altered facades and floor plans or are expected
