People are advised not to smoke at home, since passive smoking is ________ to people around them. Which is Not proper for the blank

will listen to music every time he comes across a maths problem.—You know, music is the source of ______ in life.

The new airport is built close to the freeway,and it is __________ by Bus No.2.[ ]

glish examis not difficult, is it—_____, even Tom _____ to the top students failed in it

My school isn’t far from here. It’s only__________ walk.