题目

完形填空Bythe end of the 20th century, TV show producers had begun to turn to thecheapest performers available — their audience. It seemed that anyone whowanted fame could 1 it. And some people wanted it far too much. Richardand Mayumi Heene, 2 ,launched a large balloon 2,000 meters into the air and then called a TV networkto say that their six-year-old son, Falcon, was inside it. Planes werere-routed and Denver International Airport was briefly 3 . However, Falcon was later found to have beenhiding in the family's garage the whole time. The balloon boyincident turned out to be a hoax ( 某溶液中含有NH4+、Mg2+、Fe2+和Al3+四种离子，若向其中加入过量的氢氧化钠溶液，微热并搅拌，再加入过量盐酸，溶液中大量减少的阳离子是                     （    ）     A. 只有NH4+      B.只有 Al3+        C. NH4+和 Al3+     D. Fe2+和NH4+