They changed it because the machine gun fire wouldn't let the troops advance ( charge ). It also changed it because no light Armor ( Jeeps and Motorbikes ) could get past it with out losing a crew member or 2.
it changed by... well it changed... It just changed!
The simple past tense (and also the past participle) is attacked.
no, Argentina has not changed. but the president has
The past participle is battled. This is also the case for the simple past tense.
YES, most true submersibles have a 'pilot' and a systems operator. The submersibles that do not carry people are usually called ROV's or AUV's
The past tense of change is changed.
The past participle is changed.
Deep sea submersibles help get research from the ocean floor.
Very small, if it even exists. Most submersibles do not carry cargo
alvin
The past participle is changed.
* == ==
Changed.
no
Both forms are "changed"
The past tense is changed.