MISSING LETTERS XI

The same letter can be added or inserted twice in each of the letter strings below to make complete words. The missing letter will be different for each set. #4 is a proper  name.

1. ERO

2. EUNE

    OOBA

    UITSU

    IMAM

 

3. IC

    HAI

    AYA

 

4. YKN

 

Answers:

 

1. Missing letter X:

    XEROX

 

2. Missing letter J:

    JEJUNE

    JOJOBA

    JUJITSU

    JIMJAM

 

3. Missing letter K: 

    KICK

    KHAKI

    KAYAK 

 

4. Missing letter O:

    YOKO ONO