怎样区别软水和硬水（写出方法、现象、结论）
取水样，加入肥皂水，产生大量浮渣的是硬水，产生大量泡沫的是软水．
阅读短文，判断下列句子正误。正确的在题前的括号里打“√”，错误的打“×”。
Today is March 15th. It's spring in Dalian. It's a sunny day. Some students go hiking. Chen Jie draws a
picture of flowers. John and Wu Yifan climb mountains. Sarah flies a kite. Amy reads a book, she likes reading.
Mr. Black and Miss White play chess under a big tree. They have a good time.
( ) 1. Today is March 15th, a windy day.
( ) 2. It's spring in March in Dalian.
( ) 3. Two boys climb mountains.
( ) 4. Amy likes drawing pictures.
( ) 5. Miss White and Mr. Black fly kites.
按蜕膜与囊胚的部位关系，将蜕膜分为底蜕膜、包蜕膜和真蜕膜3部分。()
