Structure and Written Expression

1. Simple photographic lenses cannot ______sharp, undistorted images over a wide field.
(A) to form
(B) are formed
(C) forming
(D) form

2. Of all the factors affecting agricultural yields, weather is the one ______ the most.
(A) it influence farmers
(B) that influences farmers
(C) farmers that it influences
(D) why farmers influence it

3. Beverly Sills, ______, assumed directorship of the New York City Opera in 1979.
(A) be a star soprano
(B) was a star soprano
(C) a star soprano and
(D) a star soprano

4. ______ of tissues is known as histology.
(A) Studying scientific
(B) The scientific study
(C) To study scientifically
(D) That is scientific studying