WASHINGTON, Dec. 14 (Xinhua) -- Twenty-eight innocent people, including 20 primary students, have been slaughtered in a mass shooting at an elementary school in the U.S. state of Connecticut. Their blood and tears demand no delay for the U.S. gun control. The massacre has triggered a new debate on gun control in the United States. However, this time, the public feels somewhat tired and helpless. The past six months have seen enough shooting rampages in the United States. Just three days ago, three people were shot dead at a shopping mall in Oregon. Two weeks ago, a football player shot...