A.Sources of illumination for microscopes
B.The detail seen through a microscope
C.Outdated microscopic technique
D.A new kind of microscope

A.Sources of illumination for microscopes
B.The detail seen through a microscope
C.Outdated microscopic technique
D.A new kind of microscope

A.that
B.what
C.which
D.how

A.as soon as
B.provided
C.so that
D.already

A.surpassed
B.overtaken
C.exceeded
D.outdone

A.example
B.understanding
C.clarification
D.explanation

A.lost
B.missing
C.absent
D.misplaced

A.lost
B.missing
C.absent
D.misplaced

A.retreat
B.conquer
C.gather
D.remain

A.They will eventually change the illumination range that they now use
B.They will provide information not available from other kinds of microscopes.
C.They will eventually be much cheaper to produce than they are now.
D.They will probably replace electron microscopes altogether.