Which statements are true of the september 11, 2001, attacks against the united states? check all that apply.
the answer is

after boarding four planes, terrorists attacked flight crews and took over the planes’ controls.
many of the terrorists involved in the attack were trained at flight schools in the united states.
the terrorists flew two of the planes into the world trade center buildings in new york city.
the planes brought down the world trade center buildings after jet fuel caused a large fire.