The TTL output stage is a rather complicated pushâpull circuit known as a totem-pole output (the transistors, diode, and resistor in the right-most slice of this TTL logic gate circuit). It sinks currents better than it sources current.
The theory for spontaneous generation refers to the idea that life can produced from nonliving things. Lazzaro Spallanzani proposed in his experiement that air was necessary for spontaneous generation.
In Italy, a lot of people are convinced that pasta was invented in China and brought to Italy by Marco Polo in the 13th century. In the book Il Milione or The Million, Marco Polo observes that he saw and tasted a lasagna similar to that which we prepare with wheat flour.