 Complete the following phrase:  By the last year of the First World War, the surviving ships were outdated, and six of this class were converted into blockships to be scuttled in the entrances to enemy-occupied ports in Belgium. The cruisers Intrepid, Iphigenia and Thetis were expended on 23 April 1918 in the raid on Zeebrugge; Brilliant and Sirius were unsuccessfully expended in the similar 