1. What makes lead a harmful substance?

A. It is highly malleable.
B. It has a low melting point.
C. It is used as an ingredient in paints.
D. It can cause respiratory disorders due to prolonged expos


2. Plastic is one of the most common materials that can be found around us. Which of the following statements is NOT true about plastic?

A. Plastics are durable and lightweight.
B. Plastics are suited for the manufacture of toys, chairs, and tables.
C.Plastics can be harmful to organisms even when disposed of properly.
D. Plastics have no direct effect on human health.


3. Asbestos is a naturally occurring mineral with many uses. Which of the following properties of asbestos makes it a harmful substance?

A. It is odorless and tasteless.
B. It is nonflammable.
C. It is stronger than steel.
D. It has high thermal stability.​