Upon receiving the bid documents, the bid inviter shall sign for and safe-keep them but may not open them.

招标人收到投标文件后，应当签收保存，不得开启。

youdao

He said that when the bombs went off, the university gates were closed, and campus security would not open them.

CNN: January 17, 2013 -- Updated 2129 GMT (0529 HKT)

Their exact aims are unclear but they have threatened to attack the capital, Kinshasa, if President Kabila did not open negotiations with them.

BBC: DR Congo crisis: M23 rebel leader 'flies to Uganda'

Boley said Tuck is wily at making sure to use the triple and double word slots, and not leave them open for him.

WSJ: Super Bowl: New York Giants Play Words With Friends