1.I am deeply honoured to be invited to this momentous occasion.

1.能应邀出席如此重要的场合，我幸。

2.Its compositional ichthyofauna differs from its consecuting fiver systems,and has momentous significance on succession of fishes and ichthyofauna dividatur in watershed of North China.

2.在鱼类区系组上，它与相邻的水有很大的差异，在我国北方水鱼类演替和区系划分上有重要的意义。