邮政通信质量有三类，即：危害邮件安全类；影响邮件时限类；造成邮件损毁、延误隐患类。
参考答案：对
China sent up Shenzhou Ⅸ manned spaceship into space successfully, which shows science and technology ______ rapidly in China.
A．have been developing
B．have developed
C．has been developed
D．is developing
男性20岁，慢性粒细胞白血病，拟行同胞异基因造血干细胞移植进行HLA配型， HLA基因位于
A．6号染色体上
B．8号染色体上
C．11号染色体上
D．14号染色体上
E．9号染色体上
