题目

下列叙述中正确的是         ( ) ①溶液都是纯净物 ②含氧的化合物都是氧化物   ③能电离出H＋的化合物都是酸 ④能电离出OH－的化合物都是碱 ⑤能电离出金属离子和酸根离子的化合物都是盐 ⑥酸和碱的中和反应都是复分解反应 A．全部             B．⑤⑥             C．③④             D．①②It was 1504,and Columbus was making another trip to the New World. Columbus and his men needed fresh water and food after three months at sea. They saw an island and went on shore. On the island there were unfriendly Indians who refused to give food to them. Columbus’ men were afraid of the Indians, but he had a clever plan. He used sign language to tell the Indians about his mysterious (神秘的) power to turn off the light in the sky. He knew about a lunar eclipse (月蚀) the next night because the information was in his almanac (天文历书). Columbus told the Indians, “ Tomorrow night I’ll turn off the light in the sky.” But they didn’t believe him . When the eclipse began the next night ,the Indians became very frightened . They begged Columbus to turn on the light again , and they quickly gave him all the food and water he wanted. Immediately Columbus and his men hurried back to the ship and sailed away in the moonless night. Columbus and his men stopped at the island because_______________. A. they wanted to meet the Indians there B. they hoped to get supplies of food and water C. they had never been on the island before D. they had planned to visit it          The Indians ___________ Columbus and his men. A. were glad to see       B. were kind to C. welcomed            D. were not kind to Columbus ________ to tell the Indians that he had mysterious power. A. used movements of hands and expressions in his face B. spoke in the language of the Indians C. drew a lot of signs D. wrote in the language of the Indians “The light in the sky ” here means __________. A. the sun     B. the moon     C. the stars     D. the daylight The Indians gave Columbus food and water because they _________. A. believed Columbus was a man with mysterious power B. were interested in Columbus’ trip C. wanted to help Columbus D. were clever