留置构造栓合格的规定是( )
A. 留置位置正确,大马牙槎先退后进,每次收退60mm
B. 留置位置正确,大马牙槎先退后进,残留砂浆清理干净
C. 留置位置正确,大马牙槎出顺直,允许偏差为±10mm
D. 留置位置基本正确,大马牙槎先退后进,上下顺直,残留砂浆清理干净
建筑地面工程基土分层虚铺的厚度当械圧实不宜大于( )
A. 400mm
B. 300mm
C. 250mm
D. 200mm
How many days will the tour guide stay in the hotel
A. Two days.
B. No more than 3 days.
C. At least three days.
D. Less than one week.
在下列存储器中,存取速度最快的一种是
A. Cache
B. 动态RAM[DRAM]
CD-ROM
D. 硬盘