1. Prepositions + -ing form.
Use the prepositions below to complete the sentences.
2. Write.
Type in the missing words to complete the sentences. Use the word in brackets.
For example:
Jim is interested (learn) Chinese. Jim is interested in learning Chinese.
3. Preposition + -ing form.
Complete the second sentence so that it means the same as the first sentence.
Turn off the lights, and then lock the door. Before locking the door, turn off the lights.
Select the file, and then open it. After selecting the file, open it.