Paraphrase (reword) the following sentence so that it's easier to understand.

"america aviation was from its very beginnings marred with sexist and racist assumptions."

What is the missing statement in step 3 of the proof? given: z1 is complementary to 22. 22 is complementary to 23. prove: m_1 = m23 m21 = m2 m2 1 + m22 = 90° m22 = m23 m22 + m23 = 180° 2 statements 21 is comp. to 22 2. 22 is comp. to 23 3. ? 4. mz1 - 90°-m22 m22+m23 = 90° 6. m23 = 90°-m22 7 m21 - m23 reasons 1. given 2. given 3. def of comp. zs 4. subtr equality prop. 5. def. of comp. 25 6 subtr. equality prop 17. trans. prop. vo