elusive
adj
(a) tending to escape or disappear; difficult to capture 逃避的; 躲避的; 难以捕捉的
a most elusive criminal 极难逮捕的罪犯.
(b) difficult to remember or understand 难以记忆的; 难以理解的; 难以捉摸的
an elusive perfume 难以捉摸的香味
an elusive word 难记的词.
Yes, and we must stop people walking on this floor until it's firm. It may be necessary to put up a notice saying Keep off. Another thing, we' ll have to drill a hole in the wall for the electric wires.
It took him some time to connect the long rubber pipe to the air supply pipe that ran round the port, but at last it was done and as a result work was able to progress much faster.