请教04/10的语法

cangcang555

04年10月

15．A challenging new area in inorganic chemistry is -------the role of transition metals in the biochemical catalysts called enzymines.

a.that of understanding

c.the understanding

 

19. Art Deed, (a style)of (design popular) in 1920 was used primarily in furniture, (jewel), taxtiles, and interior decoration.

 

32.The work (of) SOJ ,care 19^th century writer,(reflects) a concern (in) the alienating consequence,of  (condustrialization) and urbanization.

 

36.Barium is a (soft),heavy ,silvery white metallic element that (readily) reacts with (another) elements (to form) useful compounds.

 

39.(By) 1810 the 23 towns of HC, (had reached ) a remarkable (uniform) of economic development (as well as ) population density.

多谢大侠们指教

cangcang555

有人能解释一下吗？