When lovesick, what one dreads the most is dusk. Why one dreads the most is dusk? Because dusk remarks the end of a day, referring her youth is gone. And she fears to face the night herself. The new students dreads communication. When is dusk? What time is Dusk? 6 or 7pm is dusk. A teacher wants to do a practical, but she said a beaker won't work, because it has a spout. I though a beaker would work and I wanted to try it, but she reiterated it won't work and asked for something like a gas jar which the top is flat. So I didn't try it in front of her and even stole some glasses from the staff room. But they are not enough. Then I tried the practical with a beaker and it worked. Then I understood: fires require at least 16 percent oxygen content to burn. scientific knowledge is based on experimental evidence.