In that incident, none of the people including the mayor jumped into the fiver to save the drowning girl; _____, they just went away [ ]

Generally speaking, students _____the teacher, who are knowledgeable and patient.

I _______ him not to smoke, but he didn’t think it necessary.

The maths problem is ______ hard for us ______ solve.

Everything you choose in life should be based on you value.