I feel greatly honored ____ into their society. [ ]

下面的说法恰当的一项是（ ）昔吴起出，遇故人而止之食。故人曰：“诺，期返而食。”起曰：“待公而食。”故人至暮不来，起不食待之。明日早，令人求故人，故人来，方与之食。起之不食以俟者，恐其自食其言也。其为信若此，宜其能服三军欤欲服三军，非信不可也！

I’ll lend you the money only on ______you can pay ______on time.

u ______ theidea of living a low-carbon life—It sounds tough, butit is a tendency

The project turned out much more difficult than _____ [ ]