Hỏi: Mukai Chiaki, the first female Japanese astronaut, ……….. 15 days aboard the space shuttle Columbia in space before it …….. to the

Hỏi:
Mukai Chiaki, the first female Japanese astronaut, ……….. 15 days aboard the space shuttle Columbia in space before it …….. to the Earth on July 23,1994.
A. spent - had returned
B. had spent - returned
C. was spending - was returning
D. spent - was returning

B là đáp án đúng
Lời giải:
QKHT before QKĐ