SAT语法题.2010年一月的.In 1988 a Soviet icebreaking ship helped free three gray whales that had become trapped in the Arctic ice after they (had swam) into the coastal waters of Alaska to feed. had swam错了.我知道.可是我说不出原因 也不知道怎么改 after后面只能接ING吗.还是就是单纯的时态不对?
问题描述：
SAT语法题.2010年一月的.
In 1988 a Soviet icebreaking ship helped free three gray whales that had become trapped in the Arctic ice after they (had swam) into the coastal waters of Alaska to feed. had swam错了.我知道.可是我说不出原因 也不知道怎么改 after后面只能接ING吗.还是就是单纯的时态不对?
答
after后面可以加句子.这题的错误应该是SWIM的过去分词是SWUM而不是SWAM.