Associated Press: Two congressmen will hold hearings to investigate how well companies have responded to a massive oil spill in the Gulf of Mexico. U.S. Reps. Henry Waxman and Bart Stupak sent letters requesting the testimony of officials from BP America, Transocean and Halliburton. BP operates the rig, which is owned by Transocean. Halliburton worked on the rig not long before the explosion. The hearings also will look into how recovery efforts are going, and what the companies’ safety measures …