[求助]1998 08 北美

n9ga1 · 发表于 2005-5-27 08:15:00

8 In this pure state antimony has no important uses, but ___ with other substances, it is an extremely useful metal.

(A) When combined physically or chemically

(B) combined when physically or chemically

(C) the physical and chemical combination

(D) it is combined physically and chemically

答案： A

还是不明白

n9ga1 · 发表于 2005-5-27 08:16:00

谢谢帮忙~~

n9ga1 · 发表于 2005-5-28 23:08:00

不是说要和主句一致才可以省略吗？

n9ga1 · 发表于 2005-5-31 08:10:00

谢谢~~ 帮忙~~~

所属分类: TOEFL / IELTS