What does "sebum" refer to?
A: A dark substance in the skin
B: The oily substance secreted by the sebaceous glands
C: The fine threadlike strands growing from the skin
D: A thin hard layer covering the finger
A: A dark substance in the skin
B: The oily substance secreted by the sebaceous glands
C: The fine threadlike strands growing from the skin
D: A thin hard layer covering the finger
举一反三
- Which of the following refers to the outermost layer of the skin? A: sebaceous B: epidermic C: epidemic D: epidural
- Which one of the following suffixes does NOT refer to substance? （ ）.
- What does the professor mean when he says this A: Little is known about defining a substance as an air pollutant. B: The substance isn’t an air pollutant when there is a very little in the air. C: The substance can’t be judged to be an air pollutant only from its actual concentration level. D: The actual concentration level means little to peopl
- Which substance is produced by endocrine glands: A: saliva B: milk C: stomach acid and digestive enzymes D: insulin
- What does Pecola dream to have?( ) A: green eyes B: brown skin C: blue eyes D: blonde hair