Question 20: …………….. in the 19th century, my house is the oldest one in the village.

Knowledge: Shortened clauses

Explain:

When two sentences have the same subject (my house), we can reduce a clause to the form:

+ V-ing: when the clause in the active form

+ V-ed: when the clause is in the passive form

Full sentence: My house was built in the 19th century, it is the oldest one in the village.

=> Built in the 19th century, my house is the oldest in the village.