单项选择题
A.repairing or replacing
B.to repair or to replace
C.being repaired or replaced
D.to be repaired or replaced
单项选择题 The Certificate of Inspection of a damaged tank barge has expired. What certificate authorizes the barge to move to a repair facility for repair and inspection?（）
单项选择题 The “grip” of a joint represents the（）.
单项选择题 Starting motors，generators，and other spark producing devices should be mounted as high above the bilges as possible to（）.