The ordinary girl sat silently at the corner , but when the prince came over to invite her to dance , her face immediately ____________.
Evidence obtained from observation and experiment is often used to ________ a scientific theory.
.Faced with a problem,you have to ________ it first,and then try to find a solution.
Teaching pronunciation class to a mixed group of learners can ________ a teacher with many challenging problems.
All my pockets have been ________ but I can’t find my keys.
—OK,I’ve had enough of it.I give up.—You can’t________your responsibilities. (2012·江苏,26)