心机: thinking; scheming 短语和例子费尽心机 leave no stone unturned; try all ingenious ways; take great pains; cudgel one's brains; 枉费心机 rack one's brains in vain; make futile efforts
用尽: exhaust;use up 短语和例子用尽方法 use every possible means; 用尽心机 exhaust one's abilities; rack one's brains in scheming; 用尽一切气力 exert every ounce of energy