Please help me on the following sentences, is pron needed?<br/><br/>1. The person got injured in the accident is/was Mike.<br/><br/> The person who got injured in the accident is/was Mike.<br/><br/>2. The person knocking at the door was Mike.<br/><br/> The person who was knocking at the door was Mike.<br/><br/>3. The water accumulated on the ceiling was absorbed by the ceiling board causing it to drop on the floor. <br/><br/>The water accumulated on the ceiling was absorbed by the ceiling board caused it to drop on the floor. <br/><br/>The water accumulated on the ceiling was absorbed by the ceiling board which caused it to drop on the floor. <br/><br/>Your answers will be much appreciated.