When Bob and his friends came, we ______ our supper then.

When a pilot is on board to pilot the vessel the Letter（）must be hoisted.

We ( ) supper when a policeman came to the door

I remembered the day when World War II finished I was eight or nine at the time , and we heard it ___ when we were at the table

I remembered the day when World War II finished I was eight or nine at the time , and we heard it ___ when we were at the table

When our imports ______ our exports, we say we have a favorable trade balance; however, when our imports and exports are the other way round we say we have an unfavorable trade balance.

Riding on the swings(秋千）and playing with the ducks in the pond was our children's greatest pleasure when we took them to the park.

When the pilot is climbing up the ladder ,what will you say?（）

The Smiths _____ their breakfast when the morning post came.

If we carry out our plan with（）we will surely achieve our goal sooner or later.

When a tug is pulling on a hawser at right angles to the ship，and the pilot wants to come ahead or astern on the ship’s engine，care must be taken that the pilot（）.

The third officer’s duty is to（）when vessel is commanded under the pilot or captain.