水的总水头包括哪些组成部分？
A、位置水头
B、压强水头
C、流速水头
D、服务水头

After  the Norman Conquest,      1        became the la...

问答题After  the Norman Conquest,      1        became the language of the ruling upper class and       2     a lower class language.

接近顾客时，应设法在短期内建立信任。（ ）A．对 B．错

单项选择题接近顾客时，应设法在短期内建立信任。（ ）

How do they wrap fragile goods according to the video? ...

单项选择题How do they wrap fragile goods according to the video?
A、They usually wrap fragile goods all together in cartons. 
B、They usually wrap fragile goods separately by wrapping the cushioning material several times. 
C、They usually pack fragile goods in wooden cases. 
D、Fragile goods are often packed in plastic boxes.