托福考试

【单选题】
A、They defend the bone against viruses.
B．They prevent oxygen from entering the bone.
C．They break down bone tissue.
D．They connect the bone to muscle tissue.

网考网参考答案：C
网考网解析：
What is the function of the first group of specialized cells discussed in the talk document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>