________ time went by, small clever animals covered the earth and have become the most important animals on the planet.
—Susan has done well in the competition. —______. She always does well in such activities.
______ makes the people who find value in hardships different is that they are able to combine what happened with the story of their own life.
Our monitor, who by then ______ admission to Fudan University, decided to do some part-time jobs to gain more practical experience.
Taking physical exercise regularly is an effective way to avoid ______ with the flu.
The entry point tissue in the very front of eye functions as the window ______ all light has to pass on its way.