单词:
单词: 相关文章
at the drop of a hat to talk through one's hat 今天我们要给大家介绍两个和
Turn Off Your Cell Phone 关掉你的手机 We went to the movie the other night. I sat in an aisle seat as I usually do, because it feels a little roomier. Just as the feature was about to start, a blonde from the center of the row got up and starte
Every school day, about 7,000 students drop out of school(退学) in the United Stars. That's a total of 1.2 million students each year and only about 70 percent of entering high school freshman graduate each year. The problem is especially serious i
WASHINGTON, May 11 (Xinhua) -- Researchers at Brigham and Women 's Hospital (BWH), a teaching affiliate of Harvard Medical School, have identified(鉴定) a human lung stem cell that is self-renewing and capable of forming and integrating multiple bi