施工方案是指导施工活动的全局性文件。
参考答案：错
解析：施工组织总设计是指导施工活动的全局性文件。
将公式V=V0+at变形成已知V，V0，t，求a的代数式，得a=______．
His sister left home in 1998，and ________ since．[ ]
A．had not been heard of
B．has not been heard of
C．had not heard of
D．has not heard of
