Past Tense / Past Progressive

Directions: One underlined word or phrase has an error. Correct it. The European Union introduced the euro in 1999, and it was becoming common currency in 2002. Before 1999, people used different currencies.

Can parents treat all their children ______?

This test contains two types of questions: multiple choice and error correction. For multiple choice questions, simply select the correct answer for the blank. For error correction questions, write in the box the underlined phrase that contains an error, and also write the correction for it.

The WTO ensures that countries enforce ______ tariffs.

The downturn resulted ______ company layoffs.

Directions: One underlined word or phrase has an error. Correct it. At 7:15 p.m., a zookeeper at the San Diego Zoo was cleaning near the lion exhibit when she suddenly dropped her keys into the enclosure. Security guards were called immediately, but they didn’t come because they napped.

14. What happens when a leaf node is removed?

23. Vertices that are connected by an edge are said to be ___________ to each other.

2. How many edges are there in the graph?