check or cross

1. In academic writing, we should emphasize our personal opinion to explain the topic.
2. In academic writing, we must avoid the use of subordinate clauses.
3. In academic writing, we should provide evidence for the claims we make to justify our position
4. In academic writing, we should try to contract all auxiliary verbs like "do not" to "don't" or "could not" to "couldn't".
5. In academic writing, we must use more varied vocabulary.​