According to the federal official, the decline of application for citizenship was caused by
A．the increase of citizenship fee.
B．unstable economy.
C．various reasons.
D．the upcoming revisions to the U. S. citizen test.

判断题因接受不同实验处理而造成各组间的差异是组间变异。()

未分类题Which of the following is true according to this passage?A．The illegal immigrants always outnumber the legal ones in the U. S.B．The legal immigrants always outnumber the illegal ones in the U. S.C．There are about 8.5 million illegal immigrants in the U. S.D．Most illegal immigrants come from Latin America.

判断题F检验时要注意区分假设检验是单尾还是双尾的。()

未分类题From this passage, we can learn thatA．there would be no more political and social turmoil in the U. S. without illegal immigrants.B．the Washington government has two think tanks.C．the government is trying to solve the issue of illegal immigration.D．the U. S. Congress does not want to solve the issue of illegal immigration.

判断题在无法考察总体时，要从总体中抽取能代表总体的样本作为考查对象。()