Dick and Betty are sister and brother 对么

Dick and Betty are sister and brother 对么 Dick and Betty is sister and brother. Are they sister and brother? Jim and Mary are brother and sister jenny and alan are sister and brother My brother and sister are ___________ doctors. the hales are brother and sister. ( ) Kate and Jim are brother and sister?(Do or Are) Mary and Betty are tom and linda are brother and sister.they live Tom and linda are brother and sister a 改错：David and Helen are sister and brother