drivers who crashed after falling asleep did not detect any signs of drowsiness before the crash

Half of

Explanation:

It has been established by a survey or research that about half of drivers who have given reports that while driving they fell asleep.

Sleeping while driving can be a major cause of accidents and a great risk to both the driver and other road users. It could be caused by lacking enough sleep, sleep disorders, medications.

mali had been a state inside of the ghanaian empire. after ghana fell because of invading forces and internal disputes, mali rose to greatness under the leadership of a legendary king named sundiata, the "lion king." the songhai empire, already weakened by internal political struggles, went into decline.