如圖,∠ABD=90°,
(1)點(diǎn)B在直線______上,點(diǎn)D在直線______外;
(2)直線______與直線______相交于點(diǎn)A,點(diǎn)D是直線______與直線______的交點(diǎn),也是直線______與直線______的交點(diǎn),又是直線______與直線______的交點(diǎn);
(3)直線______⊥直線______,垂足為點(diǎn)______;
(4)過點(diǎn)D有且只有______條直線與直線AC垂直.