已知向量a=(1,t),b=(-1,t),若2a-b与b垂直,则|a|=( )。
2
下列关于年度成本分析的说法正确的是()。
A.年度成本分析的内容不包括月(季)度成本分析所包含的内容
B.年度成本分析的重点是对下一年度提出切实可行的成本管理措施
C.施工周期较长的项目,不需要月(季)分析,只需要进行年度分析
D.年度成本分析的依据是月(季)成本报表
Despite (1) that alcoholic beverages may (2) , a leading medical expert is advising: don’t (3) just yet. Anybody who’s ever worked in a hospital sees the hospital is full of patients that have (4) disease, but the hospital is not full of patients that have disease related to cholesterol and (5) . In an (6) in the current New England Journal of Medicine, Dr. Goldberg of Columbia University said it is time to see (7) prevents heart disease. Such a study would give (8) to one group of heart disease patients and not to another, and see (9) . In the latest study, which followed (10) over a 12-year period, researchers found that those who drank (11) drinks per week (12) of heart attack by (13) compared to (14) . The lead author, (15) Kenneth Mukamal of Beth Israel Deaconess Medical Center in Boston, insists his study is (16) . For one thing, other studies have not looked at (17) . Dr. Mukamal says (18) also appear to settle which alcoholic beverage are (19) . "Beer and spirits, beer and liquor, were most ply (20) ."