按照美国1987年的《标准产业分类》,信息技术产业是由()组成的。
A、硬件业
B、软件和服务业
C、通讯设备制造业
D、通讯服务业
参考答案:A, B, C, D
They became good friends during the war, and since then their lifelong friendship has______ tests of life and death.
A.gone through
B.got through
C.stood up
D.cleared up
普通粘土砖铺砌在水泥砂浆结合层上,水泥砂浆结合层厚度应为______。
A.5~10mm
B.10~15mm
C.15~20mm
D.20~25mm