Please some help to identify those DA (5,6,7,8). two of the are marked "N" and the other two are marked "MO" or "M0". Thanks.

 

DA stands for diode array. There are two diodes in each SOT-23 package (also SOT-323 or SC-70).

N is DAN202 with common cathode.
MO is M1MA142 with common anode.