旅客的行李分为()和()。持成人或儿童的的头等舱旅客免费行李额为()公斤,普通舱旅客免费行李额为()公斤,持婴儿票旅客免费行李额为()公斤
参考答案:手提;自理;40;20;0
There are a kind of persons who use computer to deal with data and produce some information,but they do not change the hardware system and the software system.Which kind of person are they
A.system architect
B.language creator
C.terminal user
D.computer scientist
絮凝作用是絮凝剂()上活性基团与很多颗粒表面吸附(从而使颗粒迅速地聚集成絮团。
A、体积
B、细胞
C、分子长链
D、长度