1. Name the actor that has been paired up with Leila Tong, Charmaine Sheh, and Annie Man. Name the series he paired up with them.

Steven Au w/ Leila - The Legend of Love
w/ Charmaine - Strike at Heart
w/ Annie Man - Burning Flame II

2. Name the actress that has been paired up with Kevin Cheng, Kong Wah, and Gordon Lam. Name the series she paired up with them.

Maggie Cheung w/ Kevin - Burning Flame II
w/ Kong Wah - King of Tomorrow and Yesterday
w/ Gordon Lam - Plain Love II

3. Name at least 3 couples that have paired up at least 3 times. Name the series.

Micheal Tao and Kenix Kwok - DIF I-III, Shine on You, Love Bond
Louis and Jessica - A Step into the Past, DIF IV, Man's Best Friend
Joyce Tang and Marco Ngai - Armed Reaction I-IV, Flying Fox of Snow Mountain, The Prince's Shadow

Is it Nadia Chan?

w/ Kevin Cheng in new series TRIM SHORT LEAVE LONG FATHER SON TROOP
w/ Kong Wah Happy Ever After
w/ Gordon Lam The Legendary Four Aces