倍數詞+more than(less than)

Sea ice covers 40 percent less(smaller ) than it was 26 years ago.
=Sea ice covers area ,down 40 percent from 26 years ago.
=Sea ice covers less than 40 percent as much area as it was 26 years ago.

還有個問題就是第3句的as much area as
第1個as是副詞所以as....as之間是不是只能加形容詞+單數可數名詞
變成as+形容詞+單數可數名詞+as
所以應該是as much a area as??

Your first sentence below is wrong as Jedi pointed out.

是否可以寫成Sea ice covers less than 40 percent area which it did 26 years ago.

No. 這是說26 年前covered 40%, 現在比40% 要少， 可能 10%.

補充的問題，系統不會通知原答題者，你要在意見欄裡提，否則對原答題者不公平。

Sea ice covers 40 percent less area than it did 26 years ago
海冰覆蓋面積比26年前減少了40％, 現在海冰覆蓋面積僅有26年前海冰覆蓋面積的60%. 它不是說比26年前覆蓋面積的40％少, less than 40% (比40％少)
Sea ice covers only 60 percent area as it did 26 years ago.

2012-12-27 20:21:08 補充：
Sea ice covers less than 40 percent area which it did 26 years ago.
Sea ice covers less than 40 percent as much area as it did 26 years ago.
這兩句的意思都不是 "海冰覆蓋面積比26年前減少了40％", 而是比26年前的40％少 (少了60% 以上).