题目

1. Do you think that he had e______ so many difficulties? 2. Our teacher tell us plants d_____ from seeds. 3. It’s not good for parents to s_____ their children. 4. This Sunday I am going to the b_____ garden for trip in our city. 5. Australia is very large, but the p_____ is quite small. 答案：1.experenced 2.develop  3.spoil  4.botanical  5.population60℃时将36g硝酸钾溶于204g水中，该溶液中溶质的质量分数为  ．将此溶液平均分成三等份：（1）取第一份，将温度升高到90℃，此时溶质的质量分数为  ；（2）取第二份，要使其溶质的质量分数比原来增加一倍，需加入硝酸钾固体  g；（3）取第三份，使其溶质的质量分数变为原来的一半，需加水  g．