SUBSTITUTION CLASS
\sˌʌbstɪtjˈuːʃən klˈas], \sˌʌbstɪtjˈuːʃən klˈas], \s_ˌʌ_b_s_t_ɪ_t_j_ˈuː_ʃ_ə_n k_l_ˈa_s]\
Word of the day
Aerocurve
- A modification of the aeroplane, having curved surfaces, advantages which were first demonstrated by Lilienthal.