胳膊拧不过大腿。(Gēbo nǐng bú guò dàtuǐ.)You cannot fight the city hall.; The arm is not match for the thigh.

Explanation

在进行势力或者力量对比时，人们常说“胳膊拧不过大腿”，比喻力量弱小的敌不过力量强大的，也说“胳膊扭（niǔ）不过大腿”。
People often say “胳膊拧不过大腿” when they compare powers or strength. This sentence metaphorically means that the weak can’t defeat the strong. It shares the same meaning with “胳膊扭(niǔ)不过大腿”.
Words:

反对fǎnduì:oppose;
政府zhènɡfǔ:government.

Sentences

1、 Jiǎ: Lǎobǎn wèishénme fēi yào pài wǒ chūchāi?
甲：老板为什么非要派我出差？
A: Why did the boss order me to go on business trip?

Yǐ: Bié bàoyuàn le, gēbo nǐng bú guò dàtuǐ. Nǐ hái shì gǎnkuài zhǔnbèi xínglǐ chūfā ba.
乙：别抱怨了，胳膊拧不过大腿。你还是赶快准备行李出发吧。
B: It’s no use to complain because the arm is no match for the thigh. You’d better get your package for your trip quickly.

2、 Jiǎ: Wèishénme méi rén fǎnduì zhè xiàng yì’àn ne?
甲：为什么没人反对这项议案呢？
A: I wonder why people accept this proposal without protest.

Yǐ: Gēbo nǐng bú guò dàtuǐ. Rúguǒ yǒu rén fǎnduì, zhèngfǔ huì pài jūnduì zhènyā.
乙：胳膊拧不过大腿。如果有人反对，政府会派军队镇压。
B:You cannot fight the city hall. People who oppose will be cracked down by the state army sent by the government.