SOLAR ACTIVITY
\sˈə͡ʊləɹ aktˈɪvɪti], \sˈəʊləɹ aktˈɪvɪti], \s_ˈəʊ_l_ə_ɹ a_k_t_ˈɪ_v_ɪ_t_i]\
Word of the day
international pitch
- the pitch used to tune instruments for concert performances; usually assigns 440 Hz A above middle C