艾滋病主要有以下传染途径，除了（）
A、血液传播
B、接吻
C、性接触
D、母婴垂直传播
参考答案：B
China ______ the WTO for more than 10 years, and it has brought great changes to it.
A．has joined
B．has been in
C．has become a member of
D．has joined in
包运租船方式下，航次中所产生的航行时间延误风险由（）承担。
A.承租人
B.船舶所有人
C.船东经纪人
D.货运代理人
