请问qǐng wèn:always followed by question sentence.Because literary meaning of this phase is: please( can i ) ask. Eg: qǐng wèn, qù fēi jī chǎng zěn me zǒu? ( Excuse me, how can I get to the airport?) 对不起duì bù qǐ: can be followed by a question as well as statement. The literary meaning is : sorry ( to disturb ) Eg: duì bù qǐ, wǒ yào qù xǐ shǒu jiān.(Excuse me, I'm going to the bathroom)

劳驾 lao jia（say what you want to say such as questions,requirements） in beijing dialect 不好意思 bu hao yi si(say what you want to say such as questions,requirements) in mandarin

Excuse me ...! (to ask for something) Qing3 wen4! 请问！ Excuse me! ( to pass by) Bao4 qian4! 抱歉！

一般采用：打扰一下,da2rao3yi2xia4

打扰一下da3 rao3 yi1 xia4 不好意思bu4 hao3 yi4 si1 请问qing3 wen4