She doesn’t plan her daysShe watches TV ______ evening and changes channels ______ few minutesSo for her this summer just means another boring vocation

Can I smoke here?—No, at no time　　　in the library.

he years, people have learned from ants that teamwork and perseverance are indeed two key ______ to success.

scovery was made_______, which wehadn’t expected .

What’s this? —It’s a machine which was invented in__________century in China.