单选题 All the people in the stadium cheered up when they saw hundreds of colorful balloons ______ slowly into the sky.
【正确答案】 A
【答案解析】解析：A项ascend“(渐渐)上升”；B项elevate“提高，举起，使上升”；C项float“使漂浮”；D项linger“徘徊”。