防止水传播性疾病发生的最有效方法是()。
A.选择水源
B.混凝沉淀
C.过滤
D.消毒
E.水源防护
参考答案:D
Due to the policy of free highway fees on major holidays, too many passenger cars are trapped on the highways, causing heavy traffic jams, some even _________ for several hours.
A.held up
B.broken up
C.taken up
D.given up
函数f(x)=x+ex-2在(0,1)有唯一的零点x*,现有求x*的三种迭代法:
方法一:
方法二:xn+1=In(2-xn),n=0,1···
方法三:
取x0=0.5,用所选方法中收敛较快的方法计算x*的近似值,要准确到10-2。