<span>Basal Body Temperature (BBT) is the body temperature upon waking up
or when a person is at rest. After ovulation, a woman’s BBT rises because of increase in
progesterone level. BBT swill stay high throughout the post-ovulation phase and
until the following cycle. If there is pregnancy, BBT will stay high.</span>
 
        
             
        
        
        
Limestone deposits can help researchers learn about what the area was like  thousands of years ago as Limestone can contain fossilized plants and animals.
Explanation:
- Limestone often contains fossils of shelled sea creatures. Entire reef formations and communities of organisms are found preserved in limestone.
- The types of fossils found in limestone include coral, algae, clams, brachiopods, bryozoa and crinoids.
- Limestone is a sedimentary rock made almost entirely of fossils. 
- Fossils are the remains of ancient plants and animals, like an imprint in a rock or actual bones and shells that have turned into rock. Fossils are found in sedimentary rocks and hold the clues to life on Earth long ago.
- Limestone is composed of the mineral calcite; calcium carbonate. It often has variable amounts of silica in it, as well as varying amounts of clay, silt, and sand. Limestone rocks fall under the category of sedimentary rocks that are made from mineral calcite.
 
        
             
        
        
        
Test tube babies are a babies conceived by in vitro fertilization.
in virto fertilization is a process by which an egg is fertilised by sperm outside the body.
hope this helps :)