原生质体
参考答案：用人工方法除去细菌细胞壁后剩下的完全缺壁的细胞叫原生质体。
-I'll ask the teacher about the attributive clause. I'm very puzzled about it.
-That's just ________ most of our classmates have doubt.[ ]
A．what
B．why
C．where
D．how
减免税是对税宰的一种灵活补充和延伸，具有统一性和相对稳定性。 ( )
