A. instrument B. perhaps C. behave D. vital A. return B. accuse of C. educator D. adore A. mildly B. offender C. summer D. communicate A. librarian B. lid C. relation D. difference A. trouble B. all one's life C. usual D. dolphin A. anymore B. again C. league D. trolleybus A. explain B. upset C. recorder D. ecosystem A. praise B. cause C. go climbing D. accountant A. allow B. labor C. fortunate D. fluent A. heat B. acquaint C. speak D. what's wrong