It was very thoughtful of you to send the flowers.

　　你送花來(lái)，想得真周到。

　　This intriguing book is both thoughtful and informative.

　　這本引人入勝的書(shū)既有思想性又有知識性。

　　Nancy, who had been thoughtful for some time, suddenly spoke.

　　南希沉思半晌后，突然開(kāi)口說(shuō)話(huà)。