To introduce, one stage at a time.
分阶段引介：一阶段一个地引入
To bring or come to an end, one stage at a time.
逐步撤除：一次一个阶段地结束
being or happening in (or out of) synchrony or harmony
（不）同相的（地）；（不）同步的（地）；（不）协调的（地）
the cabling work should be carried out &B{in phase with} the building work.
电缆工程应当与建筑工程同步进行。
In a correlated or synchronized way.
按阶段：用相关的或同步的方式
In an unsynchronized or uncorrelated way.
不分阶段：用不同步的或不相关的方式