2. robust   adjective   

原句: You'd also construct a robust network.

意思: strong and healthy

字源: mid 16th cent.: from Latin robustus ‘firm and hard’, from robus, earlier form of robur ‘oak, strength’. 

例句: She was almost 90, but still very robust.



3. roster   noun   

原句: A roster of speakers that runs from Bill Clinton to J.J. Abrams.

意思: a list of people's names and the jobs that they have to do at a particular time

字源: early 18th cent. (originally denoting a list of duties and leave for military personnel): from Dutch rooster ‘list’, earlier ‘gridiron’, from roosten ‘to roast’, with reference to its parallel lines. 

例句: Kelly has an excellent chance of making the opening-day roster.



4. surplus   noun   

原句: TED ran an operating surplus of more than $2 million last year.

意思: the amount by which the amount of money received is greater than the amount of money spent

字源: late Middle English: from Old French sourplus, from medieval Latin superplus, from super- ‘in addition’ + plus ‘more’. 

例句: The balance of payments was in surplus last year.



5. mingle   verb   

原句: Mingling with celebrities, writers, moguls, and their moms in a marathon bull session.

意思: to move among people and talk to them, especially at a social event

字源: late Middle English: frequentative of obsolete meng ‘mix or blend’ (related to among), perhaps influenced by Middle Dutch mengelen. 

例句: The prince mingled freely with the crowd.