班门弄斧 display ones slight skill before an expert 搬起石头打自己的脚 pick up a stone only to drop it on ones own feet 板上钉钉 Its final 半途而废 give up half way 帮倒忙 be more of a hindrance than a help
班门弄斧 display one’s slight skill before an expert
搬起石头打自己的脚 pick up a stone only to drop it on one’s own feet
