Answer to Question 1
D
Answer to Question 2
When mineral-rich groundwater permeates porous tissue such as bone or wood, minerals precipitate out of solution and fill pores and empty spaces, a process called permineralization. Another common class of fossils is molds and casts. When a shell or other structure is buried in sediment and then dissolved by underground water, a mold is created. The mold faithfully reflects only the shape and surface marking of the organism; it does not reveal any information concerning its internal structure. If these hollow spaces are subsequently filled with mineral matter, casts are created. A type of fossilization called carbonization is particularly effective in preserving leaves and delicate animal forms. It occurs when fine sediment encases the remains of an organism. One way in which some insects have been preserved is in amber, the hardened resin of ancient trees. In addition to the fossils already mentioned, there are numerous other types, many of them only traces of prehistoric life.
By reflecting most visible light, snow creates a much cooler microclimate than nearby bare ground.
California ground squirrel (Spermophilus beecheyi) in the man-made rocky shoreline of the Berkeley M
Clouds: Unusual Clouds
Distribution and Forms of Precipitation: Snow
Rainbows: Cloud and Precipitation Optics
Figure and Ground