#2 Learners’ Dictionary

① compelling
definitions：very interesting or exciting, so that you have to pay attention
example：The flim was so compelling I could scarcely take my eyes off the screen for a second.

② ultrasonic
definitions：sound waves are too high for humans to hear
example：Parisi developed the first ultrasonic toothbrush for Cavitron Ultrasonics in New York in 1967.

③ attribute
definitions：something to somebody/something.
example：I attribute that partly to discipline, partly to desire, and partly to the old transferability of skills.

④ upgrade
definitions：to make a computer, machine, or piece of software better and able to do more things
example：You’ll need to upgrade your hard drive to 120Mb before running this software.

⑤ arguably
definitions：used when giving your opinion to say that there are good reasons why something might be true.
example：Senna was arguably the greatest racing driver of all time.