Messages ______ be changed from sound into electricity before they ______ be sent by radio.

What is the best way __________ thequestion

What a touching love story! The main character Song Joongki in the Korean drama Descendants of the sun(太阳的后裔）acts very well.— Really When_______ it

I think it is ______ useful advice, so I will always remember it.

__ last night, because the ground isall wet