I wonder if you can help me when I get stuck. 
get stuck: be in trouble 遇到麻烦 
E.g. He always comes to my rescue whenever I get stuck. 
每次我遇到麻烦都是他帮我解围。 

2. Let me know at any time. 
Let me know: tell me or inform me 告诉，通知 
E.g. when you get to Beijing, please let me know and I’ll meet you at the airport. 
你到了北京告诉我一声，我去机场接你。 

1. As we cross the threshold into the next century…knowledge based economy. 
threshold n.. 门槛、门栏、(喻)开始 
E.g. Mind you step when you cross the threshold. (mind your head 小心碰头) 
过门槛的时候小心点. 
He was graduated last year and now is on the threshold of his career. 
他去年刚刚毕业,现在正是事业的起步阶段. 
Knowledge-based economy 知识经济 
E.g. Market-based /driven economy 市场经济 
State-owned enterprises 国有企业(S0E) 
overseas-funded enterprises外资企业 
Snow-covered mountain雪山