Asolid object has a density of 2.85 g/cm3. according to archimedes, what can be done to make this object float in water?
nothing can make this object float because it is too dense.
cut the object down to one third of its current size.
reshape the object so that it displaces more than its own weight of water. decrease the density of the object by making its volume smaller.

2: It's not just the capillary action, but the pull from transpiration (the evaporation of water from the tree) that is used to pull water up from the roots. 

The second question needs context. Strong bonds alone won't cause tension. I don't see how adhesion is different. High vapour pressure could do it, but it's the difference in pressures that'd cause tension (and the resistance of that pressure by the surface). So, a low and high pressure would be needed. Poorly worded question :( 

1: "Adhesion is the tendency of certain dissimilar molecules to cling together due to attractive forces." [1] 

3: The other three answere would not work. Think of a boat. 

3: If you push gas, it will be compressed(get smaller). If you push liquid it will push something else. Thus, liquids are good for transferring force. This is a hydraulic system.