37.

Answer and Explanation

Your Answer is

Correct Answer is D

Explanation

Item A/B: However "However", Still "Nevertheless", means concession, So and thus "Therefore", here is a causal relationship with the above, so A/B is excluded.

Item C: There is only one set of subject-predicates in the following sentence, so there is no need for the subject-slave conjunction when to guide, so item C is wrong.