How dose the scientist know that the substance goes through a change of state during the time period labeled B on the graph. P. s this is actually science i cant find the subject for science so who ever answers this will resive a prize

Which of the following must happen in order for productivity to increase? a. production levels remain unchanged while inputs increase. b. production levels rise while inputs decrease. c. production levels fall while inputs increase.

Which statements about the two fossil images are correct? 1. cave bears are ancestors of plateosaurus. 2. plateosaurus were present on earth before ostracoderms. 3. ostracoderms were the first to die. 4. plateosaurus died after the ostracoderms. 5. cave bears are the oldest fossils.

What is another way name for bd? cf, bd, cf, be