解析：That small country (at one time) (m_考试试题_专升本

【单选题】That small country (at one time) (must be) prosperous, (for) it enjoyed (a high level) of civilization.
A、at one time
B、must be
C、for
D、a high level

网考网参考答案：B
网考网解析：
[解析] 应改为must have been。表示对过去的肯定推测时要用must have been形式。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>