Answer:
We can wait for the colleague to finish the work on which he/she is focusing. In this way, he will have his mind diverted to listen to our request other than the other things. If we cannot wait and the request which we want to make is urgent, we can ask him in a polite manner to be attentive to out query first but only if our request cannot wait. However, we should try our best to let the colleague finish his work first so that he can be more attentive towards us.