1. When several elephants are being trained at one time, it is customary for the new arrival to be placed between the stalls of two captives whose training is already well advanced.
    几只象同时训练时，通常是把新到的安置在两头训练得很好的大象的象厩中间，

2. In textile areas it has long been customary for mothers to go out to work.
    在纺织工业区, 母亲外出工作早已司空见惯,

3. In textile areas it has long been customary for mothers to go out to work.
    在纺织工业区, 母亲外出工作早已司空见惯.

4. For instance, it is customary for Germans, particularly male passengers, to sit in the front seat with their taxi drivers, a common practice in Australia as well.
    比如，德国人，特别是男性乘客，习惯和司机并排坐在汽车前座。这在澳大利亚也很常见。