单选题 Mr. Goa ______the proposal before he looked at the guidelines.

A、 (A) writes
B、 (B) had written
C、 (C) has written
D、 (D) will write

【正确答案】 B

【答案解析】An action that is completed before another past action uses the past perfect tense. Choice (A) is the present tense. Choice (C) is the present perfect. Choice (D) is the future tense.