After leaving office in 1999, Nelson Mandela didn’t stop doing he thought was right.
It is widely believed among bioengineers _____ it will be possible to create life under laboratory conditions.
Teaching ___ child to cook will improve many of ___ skills that he or she will need later in life.
—Rather than ___ on a crowded bus, he always prefers ___ a bicycle.
Kate didn’t come yesterday, or you ________ her.
I walked in our garden, ________Tom and Jim were tying a big sign onto one of the trees.