A．It has been the site of Earth's highest wind speeds.
B．It is subject to laws that restrict experimentation.
C．It is accessible to heavy machinery.
D．It is not subject to significant changes in temperature.

A．Clear glass was easier to find than quartz.
B．Clear glass was easier to cut to the appropriate size.
C．Clear glass magnified the letters more than quartz did.
D．Clear glass was less expensive than quartz.

A．Its historical records are more detailed than those of other inventions.
B．It has little impact on social attitudes toward vision correction.
C．Its occurrence in different places at approximately the same time is not unusual.
D．It contributed to a substantial increase in the number of literate people.