381. For starters, cabin pressures at high altitudes are set at roughly what they would be if you lived at 5,000 to 8,000 feet above sea level.
譯文
對于初試者，高空艙內壓力被大體設定為相當于居住在海拔5000到8000英尺處所承受的壓力。
點睛
what引導的是介詞at的賓語從句，what在從句中充當表語。
high altitudes意為“高空，高海拔地區(qū)”。如：
This type of breathing is not considered abnormal at high altitudes. 這種呼吸在高海拔地區(qū)不被看成是不正常的。
sea level意為“海平面”。如：
The top of the hill is just 50 meters above sea level. 這座小山的山頂只有海拔50米。
考點歸納
有關set的常見短語為：
be (all) set for sth./to do sth.意為“準備好（做）某事”。如：
We are all set for victory in the election. 我們決意要在選舉中獲勝。
He was set to go when the bell rang. 他準備好要走時，門鈴響了。
set sth. aside意為“把某事物放在一邊；節(jié)省或保留出”。如：
He set aside his book and lit a cigarette. 他把書放到一邊，點了一支煙。
You should set aside a few minutes each day to do some exercises. 你應該每天抽出一些時間來鍛煉一下身體。
set off意為“開始”。如：
We'd better set off for the station immediately. 我們最好立刻動身去火車站。
