The word them in paragraph 3 refer to ______. A. gliders B. the Wright brothers
The word them in paragraph 3 refer to ______.
A. gliders
B. the Wright brothers
C. techniques
D. vehicles
Dẫn chứng “In 1900 and 1901, the Wrights tested numerous gliders and developed control techniques. The brothers' inability to obtain enough lift power for the gliders almost led them to abandon their efforts.”
Chọn B