填空题 .A. This invention is of great importance to the progress of society.
    B. It is said that celebration will be postponed to next week.
    C. Our office has recently converted to a new computer system.
    D. It's well-known that education is the foundation of a prosperous country.

填空题 5.  据说庆典将延期到下周。

填空题 6.  这一发明对社会进步有着重要意义。

填空题 7.  众所周知，教育是兴国之本。

填空题 8.  最近我们办公室更换了新的电脑系统。