In face of failure, it’s the most important to _______ a positive state of mind.
My wallet isn’t in my bag. Where I have put it?
Many children may be fond of animals, but ever think of making the study of animals their career.
The country has already sent up three unmanned spacecrafts, the most recent at the end of last March.
.______ the satellite launch drawing near, the research workers put their hearts to the test and always stayed up late.
It was in the lab, ________ was taken charge of by Professor Curie, _______ they did the experiment.