 Complete the following phrase:  HMCS Bonaventure was sold off in 1970, shortly after completing a 16-month, 11 million mid-life refit. The 1970s saw the addition of four s, which were later updated to air defence destroyers, and in the late 1980s and 1990s the construction of twelve s and the purchase of the s. In 1990, Canada deployed three warships to support 