单项选择题
A．to have a house B．to buy a new house in the suburbs C．to have a big car D．to buy an apartment in the city
A．The iron-steel bridge collapsed soon after it was built B．The iron-steel bridge has been used ever since it was built C．The iron-steel bridge didn't come into use until it collapsed D．The bridge collapsed because it was designed by a poor student
A．A Great Mistake B． A Shocking Event C． A Warning Ring D．A Wrongly-designed Bridge