Clearance is the removal of old buildings, trees, or other things that are not wanted from an area.
例句
...a slum clearance operation in Nairobi...內(nèi)羅畢拆除貧民窟的行動(dòng)The UN pledged to help supervise the clearance of mines.聯(lián)合國(guó)承諾協(xié)助監(jiān)督掃雷工作。
N-VAR
(官方的)批準(zhǔn)，許可
If you get clearance to do or have something, you get official approval or permission to do or have it.
例句
Thai Airways said the plane had been given clearance to land...泰國(guó)航空公司說(shuō)，該飛機(jī)已經(jīng)得到降落許可。He has a security clearance that allows him access to classified information.他持有安全許可，可以接觸機(jī)密信息。
N-VAR
(路面、河面與上方橋梁之間的)凈空，間隙，間距
The clearance of a bridge is the distance between the lowest point of the bridge and the road or the water under the bridge.
例句
The lowest fixed bridge has 12.8m clearance.最低的固定橋下方通行高度為12.8米。