Eng

Alternate...

更

Alter, Alternate, Change, Experience, Furthermore, More, More yet, Night, Shift

輪

Alternate, Cycle, Gear, Recur, Rotate, Stately, Take turns,, Turn, Wheel

備用的

Alternate, Back up, Stand

(Alternative, Spare)

候補

Alternate, Backup, Reserve, Secondary, Substitute

輪流

Alternate, Take turns