有四个容量都为500毫升的瓶子，分别装满海水、纯水、酒精和汽油，那么装的质量最多的是（ρ_海水＞ρ_纯水＞ρ_酒精＞ρ_汽油）（　　）

电路设计

要求一：单独闭合开关S₁时，只有L₁亮；

要求二：单独闭合开关S₂后，L₁和L₂都亮．

（1）如图是小明设计的电路，小芳认为电路不符合设计要求．分析过程如下：

①单独闭合开关S₁时，____ （选填“符合”或“不符合”）设计要求一；

②单独闭合开关S₂时，____ （选填“符合”或“不符合”）设计要求二

A：Hi，Bill！____.

B：Yes.I've already finished my homework.

A：____.

B：I'd like to work outside.

A：Me，too！____.

B：I'd like to do something to help others.Would you like to go with me?

A：Sure！Let's come up with a plan.____.In the afternoon we can visit the children's hospital to cheer up the sick children.What do you think?

B：____. But we had better join the school weekend volunteer program.

A：Good idea！We could do better then.