派生词汇 colossus n. (pl. colossi) 巨像，巨人，巨物
14. deposit ①vt. to settle 沉积
e.g.: The Nile floods the fields and deposits mud on them.
②n. something deposited, especially by a natural process 沉积物
e.g.: Valuable mineral deposits have been found in this region.
派生词汇 depository n. 储藏室，存放处;受托人，保管人
15. silt ①n. sand, mud etc carried by flowing water and left at the mouth of a river, in a harbor, etc.淤泥
e.g.: The dam can prevent the deposit of silt.
②vi. to become filled with silt 被淤塞，使塞满泥沙
e.g.: The old channel has been silted up.
派生词汇 silty adj. 淤泥的，塞满了淤泥的
Exercise从以上单词中选出最恰当的词，填入空格内。
Purgatory is supposed to __1__you from your sins.
The Israeli army __2__for the Hamas bombing.
Human heart is an__3__ of the pump.
The astronauts had developed a __4__that was military in its rigidity.
Research workers find it hard to__5__the two sets of figures.
The pessimists consider the bourgeois society is a__6__, insensate world in which innocence and decency can prove fatal.
The increase in population__7__ a greater food supply.
There remain the __8__ crumbling ruins of an ancient temple beside the left bank of the river.
If you evaporate a little seawater on a porcelain dish; on cooling, crystals of common salt will__9__on the sides of the dish.
River sediments gradually __10__ the harbor.
答案：
1. cleanse 2. retaliated 3. analogous 4. pecking-order 5.correlate
6.predator 7. necessitates 8.colossal 9. deposit 10. silted