简述围框式分离面连接螺栓的安装顺序。
参考答案：
1、对称地先上四个固定螺栓；
2、上其余的所有螺栓，垫圈和螺母；
3、用定力扳手拧紧后，退一圈，再拧紧。
It's very convenient ______ us to buy train tickets now because we can buy them either from
the station or on the internet.[ ]
A. to
B. of
C. by
D. for
携带、遛放的宠物随地便溺不予清理可处以十元以上二百元以下罚款。
