外周血中T细胞绝对数达成人水平的年龄期是（ ）。
A．新生儿期
B．婴儿期
C．幼儿期
D．学龄前期
E．学龄期
参考答案：B
句型转换。
1. I will have an English test tomorrow. (改为一般疑问句)
2.I'm going to learn to paly the piano next summer holiday.(改为同义句)
3. She is going there by bike. (对画线部分提问)
4. We will see a movie this weekend. (对画线部分提问)
5. He has to stay at home to look after his sister. (改为否定句)
垃圾填埋场上方甲烷气体含量必须小于（）。
A.10%
B.15%
C.5%
