Multiple choice

______________ I was very tired, I could not refuse to help my friend who was stuck in the desert with a broken car.

1. Even though
2. Conversely
3. Unlike

2. You need to work hard during the semester, _____________ you'll find it difficult to pass the test.

1. therefore
2. otherwise
3. both

3. I was very happy, __________ I did not want to show it to my friends who seemed annoyed.

1. but
2. whereas
3. similarly

4. The engineers thought the figures were correct. ___________, they have now discovered some errors.

1. Also
2. And
3. However