“Underground” is the only word in the English language _____ begins and ends with the letters “und”.

The doctors said that there was ___ wrong with Jane’s legs, but they could do ___ to help her.

Please write ______ me soon. I miss you very much.[ ]

I can’t connect my computer to the Intemet. There must be ______ wrong with it.

I like doing the same things _____ others.[ ]