The fearless pirates kept _______ on the waters off the coat of Somalia, from the Gulf of Aden to the Kenya border along the Indian Ocean.
A. knocking on B. knocking down
C. knocking about D. knocking at
The fearless pirates kept _______ on the waters off the coat of Somalia, from the Gulf of Aden to the Kenya border along the Indian Ocean.
A. knocking on B. knocking down
C. knocking about D. knocking at
C