骑墙的英文：
be on the hedge
serve two masters
sit on the rails

参考例句：

To act or proceed cautiously or timidly to avoid committing oneself.
抱骑墙态度谨慎地或胆怯地行动或前进以避免连累自己

That politician is always trimming.
那个政客总是采取骑墙态度。

hedge是什么意思：
n. 树篱；篱笆；界限；模棱两可的话
v. 防备；用树篱笆围住；围住；避免直接回答；修筑树篱

They are planted for hedges.
它们种起来当作篱笆。

the ditch and hedge [an obstacle]
篱沟| 篱濠[障碍

He hedged this morning.
今天早晨他修整了一下树篱。

serve是什么意思：
v. 为...服务；供应；任（职）；服役
n. 发球（权）

to serve the landlord
为地主干活

Persons serving on the Appellate Body shall serve in rotation.
上诉机构人员任职应实行轮换。

They drafted him to serve as their delegate.
他们选派他作他们的代表。

two是什么意思：
num. 二，两个
n. 两个人
adj. 两个的

Knit two, purl two.
两针朝下，两针朝上。

the better of the two
两者中的更好者

What does two and two make?
2加2等于几？