Unit 4 World of the Future
mental arithmetic: the act of adding numbers together, multiplying them, etc. in your mind, without writing them down
skate n. & v.
1) n. one of a pair of boots with metal blades on the bottom, for moving quickly on ice
Ice skates were only a $74 million business
2) v. to move on skates
The children skated on the frozen pond.
Collocation:
ice skate: one of a pair of boots with metal blades on the bottom, for moving quickly on ice
roller skate: one of a pair of boots or frames with small wheels on the bottom, for moving quickly
on flat smooth surfaces
Practice：
Explain the following expressions:
1) be skating on thin ice
to be doing something that may get one into trouble
2) get your skates on
used to tell someone to hurry
telepathy n.
the communication of thoughts between people’s minds without speaking
Psychic gifts, such as telepathy, are rare abilities.
Derivation:
telepathic adj.
helmet n.
a hard hat to protect the head
Tom had never before ridden pillion on a motorbike, but Andy the neighbor had a spare crash
helmet.
tune in
1) to realize or understand what is happening or what other
people are thinking
Try to tune in to your partner’s needs.
2) to watch or listen to a broadcast on radio or television
People get their information by tuning in to radio stations.
Collocation:
tune up: when musicians tune up, they prepare their instruments to play at the right pitch
tune out: to ignore or stop listening to someone or something
Practice:
Fill in the blanks with proper prepositions:
1) The band were tuning _________ their guitars.
2) A bored child may simply tune _________.