Ladies and gentlemen, on behalf of our government, I'd like to extend a sincere welcome and heartfelt gratitude.

女士们、先生们，我谨代表我国政府，向各位表示诚挚的欢迎和衷心的感谢。

I'd like to convey my heartfelt gratitude to you all.

我向大家表示衷心的感谢！ ！

I'd like to convey my heartfelt gratitude to you all.

我向大家表示衷心的感谢！

Now here I want to express my heartfelt gratitude to him!

此时此刻，我真心实意地感谢他。

Dear Xiaoqiang, I am writing to express my heartfelt gratitude.

亲爱的小强：我写信是为了表达我衷心的感谢。