What a table!I've never seen such a thing before .It is ----

1.答案：C.
2.
1）这是倍数表达法中的一种：
倍数词+ as + adj原级 + (名词) + as + 比较对象
2）该项答案C分别对应:否定词not + 倍数词half + as wide(形容词原级) as + 比较对象it is long
3）it is long相当于its length.
当然,as it is long,as在此做连词；而在as its length中,as在此做介词.