复合材料的优点是[ ]
①强度高 ②质量轻 ③耐高温 ④耐腐蚀
A、仅①④
B、仅②③
C、除③外
D、①②③④
答案：D
His conclusion, ______ on careful research, was acceptable.
A．to base
B．to be based
C．basing
D．based
女性的性腺器官是（）
A. * *
B.卵巢
C.输卵管
D.子宫
E.外阴
