1.During the fermentation of sugars, the enzyme which converts glucose into ethyl alcohol is :

2.The steam engine was invented by

3.What makes a lemon sour ?

4.The ratio of pure gold in 18 carat gold is :

5.In the manufacturing of safety matches, which of the following materials are used to coat the two sides on match boxes ? 1. Yellow phosphorus2. Glue3. Glass powder4. Red phosphorus