单项选择题
A．technically speaking artists draw very well. B．an artist’s drawing differs little from an architect’s. C．precision is a vital skill for the architect. D．architects must be natural artists.
A．to change the chemical structure of fuel. B．to improve on the exhaust pipe. C．to experiment with new engines. D．to monitor the amount of chemicals.
A．the weather conditions are unfavorable. B．the necessary documents are unavailable. C．the sites are inaccessible. D．some local people are greedy.