3月龄活动性佝偻病儿的最常见表现为：（）
A.方颅
B.肋串珠
C.乓乓头
D.手、足镯
E.下肢酸痛、无力
参考答案：C
投影仪是教学中常用的电教仪器，在投影仪里装有两块较大的塑料螺纹透镜作为聚光器，它的作用是______．
The artist spent years on his monumental painting, which covered the whole roof of the church, the biggest in the country.
A．archaic
B．sentimental
C．outstanding
D．entire
