Dust and dirt soon accumulate if a house is not clean regularly.
房屋不经常打扫，尘土很快就越积越多。
However, as the evidence began to accumulate, experts from the zoo felt obliged to investigate.
然而，当证据日趋增多时，该动物园的专家们感到有必要进行调查。
Dust and dirt soon accumulate if a house is not cleaned regularly.
房屋不经常打扫，尘土很快就越积越多。
