单项选择题
If laid out in（）straight line,（）human digestive tract would measure approximately thirty-foot long.
A．a...the B．/...the C．the.../ D．the...a
单项选择题 （）most common kind of fuel used by（）peasants in our district is wood.
单项选择题 Since（）beginning of photography,（）inventors have tried to make（）photographs that duplicate（）natural colors.
单项选择题 He is very famous. He is（）poet and（）novelist.
