Correct

忽而

/ hūér / 
Strokes

Definition

suddenly/now (..., now...)

Example

As an Adverb

now..., now...

1
Hūér
忽而
zhǔzhāng
主张
zhège
这个
  
,
hūér
忽而
zhǔzhāng
主张
nàge
那个

advocate one thing today and another tomorrow

2
Hūér
忽而
tánxiàofēngshēng
谈笑风生
  
,
hūér
忽而
yùyùguǎhuān
郁郁寡欢

be now cheerful and now melancholy

3
Hūér
忽而
kū
哭
  
,
hūér
忽而
xiào
笑

cry and laugh by turns