It is said that a grave of a middle aged man ______ about 2,300 BC was found by some English archaeologists in the year of 2002.

单项选择题The headmaster went to Washington ______ the first time last September.

单项选择题I'm tired out. I ______ all afternoon and I don't seem to have finished anything.

单项选择题一般而言，中学英语单元教材可以分为三大系统，它们主次分明，______是源，作业系统和图表系统是流，三者相辅相成。

单项选择题A bank is the place ______ they lend you an umbrella in fair weather and ask for it back when it begins to rain.

单项选择题In spoken English of some areas in the US, the r sounds at the end of the words（）

A. are dropped
B. drop
C. are being dropped
D. have dropped