Answer:
The correct sentence would be:
When we arrived at the trade show, some of our equipment was missing - lost in shipping - but my boss found a store nearby to lease our missing apparatus.
Step-by-step explanation:
The first word should be when not Hen. Otherwise, there would be two subjects that are not linked and make no sense in the sentence. The correct word is "when" since the sentence is telling what happened to a group of people at a specific moment and place. Also, there should be a comma after the word show. The sentence "When we arrived at the trade show" is an introductory one, so it should have a comma at the end followed by the next sentence.