This year's output increased by 20% compared to last year.

Understanding the characteristics of that plant is very important for growing it.

In chemistry class, I learned about basic oxides.

In chemistry class, I learned about acidic oxides.

This compound is a strong base.

In this chemistry experiment, we will learn about the dangers of cyanide compounds.

He was holding my hand tightly.

He was running while holding a bag.

He always carries an umbrella around.

This chemical reaction is very dangerous.