pessimist

[‘pesimist; ‘pesəmist]

中文解释： n. 悲观主义者 (pessimistic adj.)

例句： Some pessimists claim that the increased daily intakes for manufactured product may bring pressure on waste landfills, while others believe that this pessimistic prospective is less convinced.

undermine

[.ʌndə’main]

中文解释： vt. 逐渐削弱，暗中损害 (=destory?)

例句： Generally, there will be a effect that traffic jams is undermining the efficiency for citizens.