一条道路长1公里，现在道路的两侧从起点到终点每隔50米安装一盏路灯，相邻路灯间安装一面广告牌，共需要安装()。
在Excel中，若A1、B1、C1、D1单元格中的值分别为-22.38、21.38/31.56、-30.56，在E1单元格中输入函数=ABS(SUM(A1：B1))/AVERAGE(C1：D1)),则E1单元格中的值为()。
下列措施，不能有效防范计算机病毒的是()
Among the following words, “ ______ ” contains a negative prefix.
The longest river in Canada is ________.
Modern English vocabulary develops through the following channels EXCEPT ______.
The hosts apologized for ______ that some of their guests might be vegetarians.
Fish is ________ and expensive at this time of the year in this area.
The meeting _____ next week will be of great importance.
中国自20世纪60年代开始进行海洋油气资源的自营勘探和开发。（）
周煦良在 “翻译三论 ”一文中写道：直译可以分为三类，其中不包括（）
As far as Australian culture is concerned, the history of Australia can be divided into the following phases with the exception of ________.
He was ______ to withdraw from running for the presidency.