( ) is a combination of all symmetry elements in the internal structure of the crystal, specifically a combination of all symmetry elements in the unit cell.
A. Space group
B. Crystal classes
Crystal system
D. Crystal family
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______ materials compose of multiple ordered regions, which are separated from one another by grain boundaries.
In 1958, Dr. Jack Kilby of Texas instruments company invented the first integrated circuit, including 12 devices on Ge. ( )
The first CPU was Intel's 4004 microprocessor in 1971. ( )
Based on the external environment has a significant influence on the conductivity of the semiconductor, various devices including ( ) can be applied.
A. thermocouple
B. photoresistance
C. pressure sensor
D. gas sensor
E. hall sensor