Answer:
The correct answers are:
2. unattractive
5. However
Step-by-step explanation:
In sentence number 2, the correct answer would be unattractive, as we can notice the shop windows discourage shoppers because of their emptiness. Bustling means full of activity, impressive means special, important or really large, so those options cannot be considered as a correct answer. Option A could be the correct answer, but unattractive fits better at the context then frequent.
In sentence number 5, the correct answer would be however. Because introduces causes and reasons, by introducing a subordinate clause, which needs a main clause to make it complete. Therefore, it cannot be considered a correct answer. Although means in spite of something and it can be used at the beginning or in the middle of a sentence, but it doesn't have a comma afterward and it cannot be considered as a correct answer.
We use otherwise to introduce a thought or an idea that contains an opposite claim or statement and to express our disagreement. It connects two clauses where the second clause (which contains otherwise) express what would have happened if the action in a first sentence hadn't occurred. Therefore, the correct answer is however. We use however to introduce a statement that expresses contrast with the previous sentence.