Downs grasslands, commonly known as "downs," are extensive grassy plains found in Australia. These grasslands are a distinctive feature of the Australian landscape, characterized by vast expanses of open grassy areas. They play a crucial role in supporting unique ecosystems and biodiversity in Australia. Downs are often associated with pastoral activities and are utilized for grazing livestock, especially in regions with a semi-arid to arid climate. These grasslands contribute to the ecological diversity of the Australian continent.

Each year on 24th May, Commonwealth Day is commemorated. Commonwealth Day is observed on the birthday of Queen Victoria of England, who was born on 24th May, 1819, and is observed by all countries which were once a colony of the British Empire.

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.

Answer: C) Lead(II) oxide Explanation: The systematic name for a chemical is the unique name given to it by the International Union of Pure Applied Chemistry (IUPAC). The IUPAC name can differ from a chemical compound's general name.   PbO is an ionic compound since it consists of a Lead as metal and Oxygen as nonmetal. The systematic name for PbO is Lead (II) oxide. Here we need to put the (II) since lead has more than one combining capacity.