Explanation:

- A (1)____ of trucks carrying soldiers was coming down the mountain road.

- This sentence likely describes a line or group of trucks. Common words used to fill this blank could be "convoy" or "line."

- The trucks (2)_____ slowly as there had been heavy snowfall in that area.

- Here, the word that suggests slow movement might be "moved" or "drove."

- Suddenly, with a (3)_____ a huge tree on the hill side fell bringing along with it boulders and mud.

- This describes a sudden sound or event. "Crash" or "rumble" could work here.

- (4)_____, the driver of first truck stopped in time.

- This is likely an adverb or a phrase showing a quick reaction, such as "fortunately" or "luckily."

- The soldiers got down and started (5)_____ the road.

- This sentence refers to an action taken to make the road passable.

- Options:

- Altering: Changing something about the road, but not quite right for clearing debris.

- Clearing: Removing obstacles from the road.

- Moving: A more general term; doesn't specify removing debris.

- Changing: Implies modification, not specific to clearing debris.