Excuse me. 对不起，

Excuse me, are you Sarah Willson? 对不起，请问你是Sarah Willson吗?

Excuse me, could I have some water, please? 对不起，可以要杯冰开水吗？

Be careful, those are heavy. 小心， 那些蛮重的。

Hello, can you help me? 嗨，可以请你帮个忙吗？

Could you give us a hand, please? 可以请你帮个忙吗？

Could you do me a favor? 可以请你帮个忙吗？