众志成城【zhòng zhì chéng chéng】
unity is strength
[成]万众一心,像坚固的城堡一样不可摧毁,比喻大家团结一致,力量就无比强大

全国人民众志成城,终于战胜了百年不遇的大洪水。
The people of the whole country held together and defeated the severest floods in a hundred years.
重【chóng, zhòng】
(chóng) 1. again; overlap; repeat (zhòng) 2. heavy 3. attach importance to
(chóng) [形]1、重复,重叠 (zhòng) [形]2、分量大,程度深 3、不轻视

这两门课程之间不存在重叠的问题。
There is no overlap between the two courses.

这个行李太重了,我拿不动。
The luggage is too heavy for me to carry.

尊重老人是一种社会公德。
Social morals require us to respect the aged.