98-8 请教几个语法问题

wokaotoefl

14.Franklin D. Roosevelt was___ the great force of radio and the opportunity it provided

for taking government policies directly to the people.

(A) as the first President he understood fully

(B) the first president that to fully understand

(C) the first President fully understood

(D) the first President to understand fully

我用排除法选出D但是对其语法现象不甚明白  the first President to understand  其中  to understand  是什么成份？省略了什么？是定于从句吗？为什么用不定式 to?

30. From 1905 to 1920, American novelist Edith Wharton was at the height of her writing

         A                                                                               B                         C

career,publishing of her three most famous novels.

                                              D

不太明白C错在那里，正确形式应该是什么（改成什么就正确了）？

38. Because of its vast tracts of virtually uninhabited northern forest, Canada has one of the

                        A                         B                                                                    C

lowest population density in the world.

                                         D

感觉D不对，但正确形式应该是什么？

consonant

14，the first....to do

30,没发现有错误

38，densities

zqw2001126

38.  "one of ..." 后加名词复数形式,所以是densities

wokaotoefl

太感谢了!!