A、A world ban on nuclear weapons. B、Japan’s development of nuclear weapons. C、Suspending nuclear research in Japan. D、A world ba

The space shuttle Discovery has safely returned to earth after 2 weeks in earth’s orbit. Discovery commander Eileen Collins guided the shuttle to an easy landing at Edwards Air Force Base in California early Tuesday. American Space Agency officials described Discovery’s trip as wildly successful. But they refused to say when the shuttle may fly again. The Space Agency has suspended all future shuttle flights until it can discover why a piece of hard protective material broke off from Discovery. A similar incident damaged the Columbia space shuttle in 2003. Columbia was destroyed as it reentered earth’s atmosphere.
    Japan has marked the 60th anniversary of the atomic bomb attack on the city of Nagasaki. The American bombings of Nagasaki and Hiroshima ended World War Ⅱ. Nagasaki Mayor Iccho Itoh called for a world ban on nuclear weapons. He urged Americans to ask if the United States needs thousands of nuclear arms to guarantee its security. A short time later, Prime Minister Junichiro Koizumi said he would work to keep Japan free of nuclear weapons.
    In Cambodia, an opposition politician has been sentenced to 7 years in prison for plotting to overthrow the government. Cheam Channy was arrested in February after the National Assembly canceled his parliamentary protection from legal charges. He denies any wrongdoing. A court found Cheam Channy and opposition member Khom Peseth guilty. Khom Peseth received a 5-year prison sentence.
    Briefly, here again is the major news of the hour.
    The American space shuttle Discovery has safely returned to earth.
    Japan has marked the 60th anniversary of the atomic bomb attack on Nagasaki. And in Cambodia, an opposition politician has been sentenced to 7 years in prison for plotting to overthrow the government.
16. How did American Space Agency officials describe Discovery’s trip?
17. What did Nagasaki Mayor call for?
18. What was the charge against the two opposition politicians?