a.

1. （两个）交替的，轮流的
   According to the weather forecast, there will be a week of alternate rain and sunshine.

   根据天气预报，下礼拜时雨时晴。

2. 间隔的
   They saw each other on alternate Sundays.

   他们每隔一个星期天相会一次。

3. 供选择的；供替换的[B]

n.

1. 【美】代理人；代替者；候补者[C]
   We have several alternates on our team.

   我队有几名替补队员。

vt.

1. 使交替，使轮流[（+with）]
   Our boss alternates kindness with severity.

   我们的老板时而和蔼，时而严厉。

vi.

1. 交替，轮流[（+with/between）]
   For the next few days he alternated between hope and fear.

   其后几天中他时而满怀希望，时而充满恐惧。

v.

adj.

1. every other.
   ▸(of two things) each following and succeeded by the other in a regular pattern.
   ▸Botany  (of leaves or shoots) placed alternately on the two sides of the stem.
2. chiefly N. Amer. another term for alternative.

n.