根据汉语意思完成句子。

1. 吃药前先看看瓶子上的说明.

Please look at the _______ ______ the bottle before you have the pills.

2. 他在给我的同学们做报告.

He is ______ a _____ ______ my classmates.

3. 老师让Jenny谈论一下她的家人有什么爱好.

The teacher told Jenny to ______ ______ what hobbies her family_______.

4. 去年他加入了一个新的足球俱乐部.

He _______ a _____ football ______ last year.

5. Mary说园艺是令人愉快的,而且很容易学.

Mary says that gardening is _____ and ______ ______ ______.

将6.2克氧化钠粉末投入43.8克水中，完全溶解后，计算所得溶液中溶质的质量分数．