Ask students to write three (or more) questions about the object they are observing that might be answered if they observed the object with a more powerful microscope.
(students; to write; three (or more) questions about the object) (they; observed; the object) (they; are observing; that might be answered if they observed the object with a more powerful microscope)
students they they
to write observed are observing
three (or more) questions about the object
the object
that might be answered if they observed the object with a more powerful microscope