英语时态语法分析A massive winter storm packing up to a foot of snow,strong winds and icy temperatures slammed into the northeastern United States on Tuesday,canceling flights,closing government offices and sending children home from school.哪位帮我分析一下这个句子的语法,主要是说这个时态,现在进行时和过去时这方面的,

英语时态语法分析
A massive winter storm packing up to a foot of snow,strong winds and icy temperatures slammed into the northeastern United States on Tuesday,canceling flights,closing government offices and sending children home from school.
哪位帮我分析一下这个句子的语法,主要是说这个时态,现在进行时和过去时这方面的,