The success of a government should be measured ________ the happiness of the people as well as the development of economy.[ ]

It is useless to argue with him You might just____ go to the seaside to argue with the sea

____________and evaluated the information, I help other scientists to predict where lava from the volcano will flow next and how fast.

It is _______to work out this problem You needn’t go to the teacher

oblem with seeing famous tourist attractions is the steady＿of people all trying to see the place at the same time, so I doubt whether it is worth it.