Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions

Many people believe only animals are endangered. They think wild plants can just grow back after damage. This is not true. Our plants are declining at an alarming rate. Among them are some of the most beautiful and useful species on Earth. The importance of plants to life on Earth is immeasurable. The landscape and wildlife we enjoy, the food we eat, even the air we breathe is connected to plant life.

Plants support wildlife. The U.S. Forest Service has stated that for every plant species that goes extinct, up to 30 other species of plants, insects and other animals may also decline. Plants provide the food and habitat for wildlife.

Plants support a healthy environment. They provide clean air, help hold soil in place, clean water, moderate wind and water impacts, and shade the earth.

Plants support people. Plants give many gifts to man. They provide food, fiber, and fuels. Many plants are known to contain chemicals that can be used to treat human illnesses. Others have the ability to fight agricultural pests and improve existing crops.

This is a real crisis. Habitat destruction, over collection, and other environmental damage are eroding our natural plant communities. Some species have declined to such small numbers that a bad storm or a plant collector could wipe them out in minutes. Without intervention, they will be lost forever.

Food, fiber, fuels and chemicals that can be used to treat human illnesses are the ______ plants give us.