定冠词加与不加，有什么道理的吗，我怎么老是想着在括号内加个冠词才好呢，好困惑我这个坏毛病:

However, (the) rescue operations are proving difficult. 

If (the) explosives are used, vibrations will cause the roof of the mine to collapse. 

(the) Rescue workers are therefore drilling a hole on the north side of the mine. 

They have been told that (the) rescue operations are progressing smoothly. 

Though they are running short of (the) food and drink, they are in good spirits. 

Because of this, (the) rescue workers are drilling a hole through (the)hard rock, yet (the) progress is slow.