Which three sieves?

哪三个筛子？

“Normally, our memories are like sieves, ” he says.

“通常，我们的记忆就像是个筛子，”他说。

The prospects for composite molecular sieves was expected.

并对复合分子筛的发展前景进行了展望。

"Three sieves? Which three sieves?" the man asked with puzzlement.

“三个筛子？哪三个筛子？”那人不解的问。

"Three sieves? Which three sieves?" the man asked with puzzlement.

“三个筛子？哪三个筛子？”那人疑惑的问。