Answer: A) Sulphur dioxide Explanation: Air pollutants are solid particles, gases, and liquid droplets in the air that can adversely affect ecosystems and the health of humans.   Major ambient air pollutants include toxic metals, polycyclic aromatic hydrocarbons, benzene, particulate matter (PM), nitrogen oxides, sulfur oxides, carbon monoxide, and ozone. Power plants, factories, and vehicle and air traffic are the most important anthropogenic sources of air pollution.   In addition, natural sources such as wildfires and volcanic activity contribute to ambient air pollution.

Answer: B) Some inherited genetic mutations can be good for the offspring. Explanation: Mutations are accidents in the copying of DNA. A genetic mutation is a random change in the DNA that is passed on further generations of cells and or organisms.    Genetic mutations are accidental changes in the DNA in the germ cells or early in the formation of the embryo. These changes if they are in the germ cell will be passed on to other organisms formed by sexual reproduction or asexual reproduction. An example would be the golden delicious apple. A lost of genetic information due to a mutation resulted in a different color of fruit.   Genetic mutations that cause diseases are not always passed on to offspring.

Most building codes require ceiling fans to be mounted on special fan-rated boxes made of metal or strong plastic with deep-threaded holes for the mounting screws. The box must be mounted firmly by attaching it directly to a framing member or using a fan-rated brace.

1. Ornithology is a branch of zoology that studies birds. It studies different species of birds, their size, shape, colour, behaviour, habitat, reproduction and other aspects.

2. Ornithologists use a variety of methods to collect information about birds, such as field surveys, bird watching, studying bird behavior, and studying fossils.