Grammar exercise 2 of 2 语法练习2
Use 在 as “When 在 (zài) comes after the verb in Chinese grammar” explains it, through 13 items over 7 of its example sentences: fill the gap where the word was taken out, and put the words of each sentence back in order.
When 在 (zài) comes after the verb in Chinese grammar
13 items. Each one you miss comes back later in the same sitting.