In Rt△ADC, ad = CD tan 30 = 2133 = 213 = ≈ 6.33 (m), …2 points.

In Rt△BDC, BD = CD tan 60 = 213 = 73 ≈12.11(m), …4 points.

Then ab = ad-BD = 36.33-12.11= 24.22 ≈ 24.2 (m) ... 6 points.

(2) speeding.

Reason: ∵ It takes 2 seconds for the car to go from A to B,

∴ The speed is 24.2÷2= 12. 1 (m/s),

∫ 12. 1×3600 = 43560 (m/h),

∴' s speed is 43.56 km/h, …9 minutes.

∫ More than 40 km/h,

∴ This school bus is speeding on section AB ... 10.