1. reading - present tense
2. paid - past tense
3. Laughing - present
4. growing - present
5. chosen - past
A participle is a verb that is used as an adjective or a noun. For example, in sentence 1, reading is describing the type of glasses, #2 paid is describing the type of volunteer, etc. Present tense participles usually end in -ing, past tense in -ed.