In a downhill entertainment project, a person sits in a hanging basket, and the hanging basket slides down along an inclined steel cable through pulleys. As the picture shows, a person is sitting in the hanging basket. Solution: When the cable is smooth, the acceleration is: a = (m+M0) gsinθ m+M0 = gsinθ.

At this time, the acceleration of the hanging basket is also gsinθ, and the acceleration of the hanging basket is:

a′= MGS inβm = gsinβ，

It is known that when the cable is smooth, θ = β. When the cable is not smooth, θ ≠ β. So, A is wrong.

B, isolate people and hanging basket analysis, using sine theorem: mgsin(90 +θ θ? β) = f，sin β = Tsin (90？ θ),

The solution is: f = mgsin β sin (90+θ? β),

So the acceleration is: a=gsinβcos(θ? β).

Zhang Liwei of rope: T=mgcosθcos(θ? β). So B and C are wrong and D is right.

Therefore, choose: d.