To make members of a team perform better, the trainer first of all has to know their _____ and weaknesses.

Parts of the cave have been badly affected by rain and           to the air.

One of the main __________ of the summit was “sustainable development”,or the question how we can continue developing the world without damaging the environment.

Though this kind of _______ has some _______, it is good enough for construction(建筑).

I think our company lays too much ______ on cost and not enough on quality.