Last two: 12a A mark in old documents to show spurious words or passages. _b_l_s 6 letters 10d In showjumping a test of the horse's ability to jump. P_i_s_n_e. 9 letters. Thanks in advance
Last two please; 10d, An artifical language, a modification of Esperanto. 3 letters. - - O 18d, Colourless gas with chlorine like odour. 5 letters. O-O-E. Thanks in advance