launch

v.

to put (a new product) on the market (usually spending money on advertising it) 推出 （新产品）

Unit 2

lifelong

a.

extending throughout one's life 终生的

Unit 4

limit 

n.

a point or line beyond which something does not extend; boundary 限度

Unit 1

lobster

n.

large bluish black shellfish with eight legs and two long claws  龙虾

Unit 5

loyalty

n.

being true and faithful  忠诚

Unit 4

lurk

v.

to exist unseen 潜在

Unit 9