Facultatively
特許地; 能力地; 偶發(fā)地; 兼性地
??? 情景例句
how could I live in Los Angeles
我怎么能住在Los Angeles
Small gains bring great wealth.
小益聚大財(cái)，薄利成巨富。
easily obtainable from the lunar rocks in the form of liquid oxygen.
從月球上的巖石中很容易提煉出液態(tài)氧，