乙型病毒性肝炎患者传染子代的主要方式为
A．消化道传染
B．注射血浆制品
C．输血
D．母婴垂直传播
E．密切生活接触
参考答案：D
The most important _____ of his speech at the G20 summit was that we should all unite to fight against the financial．
A．element
B．spot
C．view
D．point
()可以帮助我们进行样本跟踪、聚类分析和关联分析等工作。
