whenever necessary是什么意思？

• firmness
• modernize
• peeping
• searches
• 解决方案英文
• ticket
• giraffe
• lesson
• 队长的英文
• 参与者英文
• panicked
• cloud
• PEGGING
• erased
• bothering
• satisfaction
• approaches
• BARRIE
• front
• various
• 领域英语
• default
• tourist
• theatre
• committing
• 权限英文
• aspect
• banger
• sweater
• begins

• 方案英语
• 缺陷英文
• conflict
• 实施英文
• candy
• 分配英文
• rice
• permitted
• volume
• narrow
• disappointed
• 参数英文
• toxicity
• repeat
• pear
• fake
• 抛弃英文
• lycopene
• tomato
• prompt
• crayon
• 导师英文
• profile
• explore
• supper
• 来源英语
• client
• failure
• scared
• predict

• hold sb down
• hold sb to
• hold the line
• hold to sth
• homestay
• in favour of
• in line for
• in one
• in the air
• in the hands of
• in the main
• keep at sth
• keep away from
• keep in with sb
• keep it up
• keep on doing sth
• keep sb down
• keep sb on
• keep sb out of
• keep sb up
• keep sth from
• keep sth in mind
• keep sth on
• keep sth to oneself
• keep to sth
• know better than