Vibes
CJ said the text you quoted was full of ambiguities.
I have to say, I agree. There is almost nothing in that paragraph that is correct.
"Drag,thrust,lift and weight.When thrust and drag are in equilibrium, an aircraft will maintain a steady speed.For an aircraft to accelerate,thrust must exceed the value of drag.When lift and weight are in equilibrium,an aircraft will maintain a steady,level attitude.For an aircraft to climb,lift must exceed weight of the aricraft. In a banked turn,weight is a constant,but lift is lost due to the effective reduction in wingspan.Therefore,to maintain altitude in a banked turn,the lift value needs to be restored by increasing speed and/or the angle of attack."
The stuff in red is wrong, or only true in particular circumstances (that are not specified). The stuff in green is correct.
IF its quoted correctly, then the book seems (to me) to be of very dubious quality.
Now, you can take that opinion or leave it; neither I (nor CJ) are obligated to go out and buy it to conduct a full review for your benefit. Likewise, I am not required to provide you with a complete lesson covering these topics; (although I am available for consultancy for a very reasonable rate!).
pb