The gas price keeps rising, ________ an average of 7.7 yuan per liter this month.
| A．hit | B．to hit |
| C．hitting | D．hits |
Dr．Frank failed many times but he finally _______ to find a successful way to solve the problem．
| A．broke off | B．broke up | C．broke down | D．broke through |
—Are you pleased with what he has done?
—Not a bit ．It couldn’t be ________．
| A．so bad | B．much better |
| C．any worse | D．best |
_____ scores of times , but he still couldn’t understand it ．
| A．Having explained | B．Having been explained |
| C．Though it was explained | D．It was explained |
We waited and waited．_________ we had been looking forward to ．
| A．Then came the hour | B．Then did the hour come |
| C．Then the hour came | D．The hour then came |
________ their son away to college, the old couple got more room in the house．
| A．As | B．For | C．Through | D．With |