1·The project will not be plain sailing.
这个项目不会是一帆风顺的。
2·But it won't be all plain sailing.
但这将不会都是一帆风顺的。
3·Of course, China-EU relations are not always plain sailing. It also experienced difficulties and twists and turns.
当然，中欧关系并非总是一帆风顺，也曾经历困难和波折。
4·Life is not plain sailing, but always optimistic to live.
人生总是不会一帆风顺，但总是要乐观的活下去。
5·Life can not be plain sailing, learning the same.
人生不可能一帆风顺，学习同样如此。