Scientists from different countries are trying to_______ a good way to solve the energy problem.

This kind of watch is much _____ today than last month. Would you like to have one— Really I’ll take one.

The president ordered that no time should be lost, and directed one of his high officials to __________ the matter in person.

Someone who lacks staying power and perseverance is unlikely to _____ a good researcher. [ ]

Is everyone here— Not yet．Look，there ______________ the rest of our guests!