This bill was due two weeks ago, but I forgot to pay it.这个账单两周之前就到期了，但我忘记支付了。

dull adj. 钝的；（感觉或理解）迟钝的

The butcher deaf and dumb since birth.她是天生的聋哑人。

dump vt.倾卸，倾倒

Who dumped all these books on my desk?是谁吧这些书扔到我桌子上的。

durable adj.持久的；耐用的

Our friendship has proven to be durable because it is based on mutual respect and honesty.事实证明，我们的友谊是持久的，因为它建立在相互尊重和诚实的基础之上。

dynamic adj.动力的；动态的

The markets are dynamic and a company must learn to adapt itself to this fact.市场是动态的，公司必须学会适应。

earnest adj.认真的；热心的

Thestudent studied constantly.那个认真的学生不断地学习。

echo v.发出回声；反射 回声，回音

The hills echoed his shout.大山传来他叫喊的回声。

An echo bounced off the bluff.从悬崖上传回一阵回音。

economical adj.经济的；节俭的

Comparing prices is an economical way to shop for groceries.购买食品杂货时，比较价格是一种省钱的方式。

edit vt.编辑，校订

You must edit this video before it goes on television.这段视频在电视上播放之前，你必须对其进行编辑。