句型转换。

1. They walked to the Summer Palace yesterday. (同义句)

    They             to the Summer Palace                          yesterday.

2. I think he will come back soon. (否定句)

    I                         he             come back soon.

3. The classroom is opposite the library. (划线提问)

                 is the classroom?

4. I have three kilos of ham. (划线提问)

                                         of ham do you have?

5. I went to the fashion show last Friday. (划线提问)

                            you go to the fashion show?

在“探究串联电路电压特点”的实验中：

（1）请画出与图对应的电路图，并在电路图中标上L_l、L₂；

（2）某次测量时，电压表的示数如图所示，则此时灯L₁两端的电压为_________V；

（3）某同学在测量了灯L₁两端的电压后，断开开关，然后将AE导线的A端松开，接到D接线柱上，测量灯L₂两端的电压，这一做法存在的问题是___________________________________．