B to vary表示目的 同时有歧义 是指the growth varies 还是 is projected varies
For these storms is projected 表达没有projected for these storms 好
C vary 应为varies. Growth为单数
D which指代前面的storms 同时整句话找不到谓语
E are projected应为is
同时句子Main idea varies widely 应为main verb

A中主干意思是the growth varies widely.强调growth的性质。
B 的主干意思是the growth is projected to vary widely.强调growth被预测为会怎样变化。

C应该是varies

B to vary 为了。 不对
C 主谓不一致
D 没谓语
E 主谓不一致

B选项：the growth for these storms不合语言习惯；the growth...is projected...to vary widely的对象是谁the growth还是projected的程度；
C选项：the growth主语，谓语动词vary用单数；
D选项：没谓语的句子
E选项：are projected中are 换成is

RON：main idea should be in the main clause
B错

projected for these storms修饰the growth
主干：the growth in different computerized weather mode varies.
in different weather mode做状语修饰整句话

s()+v+c

A和B：注意原句表达的是storms被project，而不是growth被project