16.We agreed _______more specific payment terms.

A.on                                                                B.in

C.to                                                                 D.at

17.Extra expenses are to be borne _______me.

A.through                                                         B.with

C.by                                                                D.for

18.The consignment is delivered _______all the charges paid.

A.in                                                                 B.by

C.with                                                              D.through

19.Owing _______unusual shortage of stock, this offer is made subject to the goods being unsold.

A.for                                                                B.at

C.to                                                                 D.with

20.There are trade exhibitions going on all over China _______this time of the year.

A.at                                                                 B.from

C.in                                                                 D.for