go on using energy so wastefully, __________ are that our oil wells will be dried up before new energy sources can be found to replace oil.

He worked hard to ________ some money for his retirement.

I want to be very careful to talk only about ____ we’ve formally tested.

I ______ the poor rabbit,but I didn’t have the right drugs with me at that moment.[ ]

You may imagine what great difficulty I had ________ complicated ideas in simple English.