fall behind (sb/sth)
be overtaken (by sb/sth); fail to keep level (with sb/sth) 落後於(某人[某事物])
The major world powers are afraid of falling behind in the arms race. 世界各大强国均惟恐在军备竞赛中落後.
France has fallen behind (Germany) in coal production. 法国在产煤方面落後(於德国)了. fall behind with sth fail to pay for sth or to do sth for a period of time 逾期不为某事物付款或不做某事
Don´t fall behind with the rent, or you´ll be evicted. 不要逾期不缴房租, 否则会被逐出.
I´ve fallen behind with my correspondence. 我积压了许多信没回.