题目

DNA分子的一条链中（A+G）/(T+C)=0.4，上述比例在其互补链和整个DNA分子中分别是 A.0.4和0.6 B.2.5和1 C.0.6和1 D.0.6和0.4 答案：BLook over there-there's a very long, winding path________up to the house. [     ]A．leading  B．leads C．led  D．to lead