回答

・Thank you very much.
・Thank you from the bottom of my heart.
・I really appreciate it.

「從心底謝謝你。」。
Thank you from the bottom of my heart.
Thank you very / so much.
I really appreciate it.

ex. 他們的援助，我無論如何感謝都不足以表達。
No matter how much I appreciate their help, it's not enough.
No matter how～＝無論如何…也

ex. 感激之情無法用言語表達。
I'm so grateful that I can't say it in words.

有幫助｜0