The paintings of Da Vinci are more popular than Michael Angelo. / As far as plans for school construction in the future, we expect the school board to take action in the next board meeting.

Question 49:
The sentence is: "The paintings / of Da Vinci / are more popular / than Michael Angelo."
The error lies in the comparison. The sentence compares "the paintings of Da Vinci" (an object) with "Michael Angelo" (a person). For a logical comparison, you must compare like with like. It should compare Da Vinci's paintings with Michael Angelo's paintings.

The corrected sentence would be: "The paintings of Da Vinci are more popular than those of Michael Angelo" or "The paintings of Da Vinci are more popular than Michael Angelo's paintings."

The error is in part D.

The final answer is $\boxed{\text{D}}$

Question 50:
The sentence is: "As far as plans for / school construction in the future, / we expect the school board / to take action in the next board meeting."
The introductory phrase "As far as plans for school construction in the future," is grammatically incomplete. The phrase "as far as X" typically requires a verb to complete the thought, such as "as far as X is concerned" or "as far as X goes." Without this completion, the phrase is awkward and ungrammatical.

A correct phrasing would be: "As far as plans for school construction in the future are concerned, we expect the school board..." or "Regarding plans for school construction in the future, we expect the school board..."

The error is in part A.

The final answer is $\boxed{\text{A}}$