Bo leh, my eldest son is now head of Math in a secondary school, it took me 2 years trying to get born him..then I ask the doctor, he asked me what I work as, i told him Taxi driving, then he replied, no wonder...your sperm tend to swim slower than other due to prolong sitting position, yet the dryness of the aircondition further hampered yr sperm vitality,..he told me to switch job for a while...and that was how I change to casket driving, and my first son was conceived after I change job