预应力先张法的缺点是成本较高、施工技术要求较高、易造成事故。
参考答案：错
(2013·辽宁五校协作体第一次联考)________ about the man wearing sunglasses during night that he was determined to follow him.
A．So curious the detective was
B．So curious was the detective
C．How curious was the detective
D．How curious the detective was
钢和铁的碳含量界限是（）。
A、2.11%
B、4.3%
C、0.77%
D、0.22%
