Why should you never smell a chemical directly? A. Many chemicals have no smell.
O B. All chemicals smell the same.
C. You cannot learn anything by smelling.
D. Some chemicals can hurt your windpipe.

Which of these statements is true about autotrophs, but not heterotrophs? a. they use sugar and oxygen to make carbon dioxide and water.b. they use chlorophyll and oxygen to make carbon dioxide and water.c. they use sunlight, water, and carbon dioxide to make sugars.d. they use sunlight, water, and oxygen to make chlorophyll.