下列各组物质的水溶液不用试剂无法鉴别出来的是
A.NaOH、AlCl3
B.CuSO4、BaCl2
C.NaAlO2、HCl
D.MgCl2、AlCl3
答案:D
Ladies and gentlemen, please remain _____ until the plane has come to a complete stop. [ ]
A. seated
B. seating
C. to seat
D. seat
使用射孔器推车拉运射孔器时,可能会造成射孔器滑落,砸伤人员,在拉运时应安装好挡板或挡杆,请问拉运102型射孔器时最多可以摆放几层?