單項(xiàng)選擇題后張法預(yù)應(yīng)力混凝土,當(dāng)曲線預(yù)應(yīng)力鋼筋或長度大于30m的直線預(yù)應(yīng)力鋼筋,一般采用()

A.一端張拉
B.兩端張拉(24M為界限)
C.一端張拉或兩端張拉均可