Which of the following describe glands? Check all
that apply
a structure that secretes substances through
a duct
a thin layer that separates or connects
Structures inside the body
a structure that secretes hormones into the
bloodstream
a structure usually made from connective and
epithelial cells

Explanation:

2, and 3

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.