as close as an oyster

例句：

1. 1.The two countries are as close as an oyster in terms of their political relations.
   这两个国家在政治关系上非常接近，就像牡蛎一样。
2. 2. They were as close as an oyster in the past, but now they have drifted apart.
   他们过去非常接近，但现在已经疏远了。
3. 3.In this case, the two teams are as close as an oyster in terms of scoring chances.
   在这个情况下，两支球队在得分机会上非常接近，就像牡蛎一样。