Meaning of 'assure'

[roland]

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #118 "Passive Tense Forms", question 7

I can assure you that this box ......... never been opened before I opened this morning.

(a) was
(b) will
(c) is
(d) had

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #118 "Passive Tense Forms", answer 7

I can assure you that this box had never been opened before I opened this morning.

Correct answer: (d) had
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what?a the meaning of:assure

[Alan]

Hi,

Assure means I can promise you/I can guarantee to you.

Alan
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English as a Second Language
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