A：加热
B：加入硫酸溶液
C：加入氢氧化钠溶液
D：降温
He's a fashion designer who's always swum against the stream；his work is very ________.
长江干流的水能资源主要集中在（ ）
根据意思写出相应的词语
①原形容水势广大的样子。后形容事物的广阔壮大，或前进的人流声势浩大。____
②比喻像乌龟的头缩在甲壳一样藏起来 ____
