为了探索昆虫交配求偶与信息传递之间的秘密，进行如下实验．

实验一：将某昆虫未交配的雌虫（只有未交配的个体才能分泌性外激素）放在诱捕器中，将诱捕器悬挂于田间，一夜后，发现捕捉到许多同种雄虫．

实验二：将未交配的雌虫先放到封闭的玻璃管中，再放在诱捕器中，将诱捕器悬挂于田间，一夜后，未发现捕捉到雄虫．

实验三：将未交配的雌虫腹部用小刀割下，再放在诱捕器中，将诱捕器悬挂于田间，一夜后，未发现捕捉到雄虫．

实验四：将未交配的雌虫放在诱捕器中，在诱捕器的周围浇一桶汽油，将诱捕器悬挂于田间，一夜后，发现捕捉到许多同种雄虫．

根据上述实验，回答下列问题．

    Hello, everyone! I am your1 today. First, I'd like to 2 you something about London before we3London is a very big city of England. The people here are friendly. They are always 4 to tell visitors something about the city.

    London is a busy place. People_5hard. They are very 6 all the time (一直). London is also a very beautiful city. It has a lot of parks and gardens (花园). When you are in London, you can7the British Museum. It can tell you a lot of 8stories. You may also visit9 place. It is the River Thames. It's long and wide. There are many boats on the river.

    May you have a good10！We will get to London in two hours. Now let's have a guessing game.