The book became a best seller.

这本书成了畅销书。

This product is a best seller.

该货是畅销货。

His first book was a best seller.

他的第一本书很畅销。

Her new book is already a best seller.

她的新书已成了畅销书。

Watermelon is always the the best seller.

西瓜永远最畅销。