将所有同类产品储存在一起的传统式仓库是()
A、存货单元式仓储
B、劳动密集式仓储
C、对接仓储
D、立体仓储
参考答案:A
Apart from his monthly salary as a sales manager, he also gets a travel _______ that covers hotel bills. [ ]
A. insurance
B. circumstance
C. allowance
D. competence
己知点E、F分别在正方体ABCD-A1B2C3D4的棱BB1、CC1上,且B1E=2EB,CF=2FC1,则面AEF与面ABC所成的二面角的正切值等于( )。