Question

The biggest threats to Christmas Island crabs during their annual migration are _______.

Answer 1

Answer:

c.  Automobiles.

A clerestory is a high wall that contains mainly of glass structure that is made for sunlight or for a clear view and fresh air.

Explanation:

The migration of hundreds of red crabs on Christmas Island is Australia is one of the most fascinating and spectacular acts of migration to the sea. These bright red crabs leave their burrows on Christmas Island and leave in millions towards the sea. And the biggest threat to this migration is the cars and vehicles that pass through, on the roads which the crabs had to cross to get to the open sea.

A clerestory is a clear section of a wall or a side of the wall that is made up of mostly clear/ glass structure to allow fresh air from outside and also for the clear view and sunlight. In this structure, a part of the wall is made of glass and not concrete so that it is 'open', for fresh air and light.