mailbag

n.

a letter carrier's shoulder bag 邮袋

Unit 9

maintain

v.

to keep something in good condition or working order 保养；维修［maintenance n. 保养；维修］

Unit 2

malicious

a.

intended to harm others  恶意的

Unit 6

management

n.

group of manages or directors 管理部门

Unit 7

manufacture     

v.

to make goods on a large scale 大量制造

Unit 1

marketer

n.

a businessman or a firm that sells goods in a market  商人或商号

Unit 5

merchandise

v.

to buy and sell (goods) 买卖

Unit 1

merchant

n.

a person who buys and sells goods, esp., of a particular sort, in large amounts  商人

Unit 6

microwave

n.

a very short electromagnetic wave used in radio and radar, also in cooking  微波

Unit 5

mobility

n.

the quality of being able to move or to be moved quickly and easily 流动性；机动性

Unit 4

motionless

a.

without any movement  一动不动的

Unit 7

mouth

v.

to say 说出

Unit 9