Complex sentence: BEST, "Boosting Engineering, Science, and Technology", is a national robotics 6-week competition in the United States held each fall, designed to train high school students for possible engineering jobs.
Split into simpler sentences: BEST, "Boosting Engineering, Science, and Technology", is a national robotics competition in the United States. BEST Robotics is a 6-week competition each fall, designed to train high school students for possible future engineering jobs.