非细胞型微生物的特点是
A．无典型细胞结构，仅由核心和蛋白质衣壳组成，核心中只有一种核酸，只能在活细胞内生长繁殖
B．有典型细胞结构，仅由核心和蛋白质衣壳组成，核心中只有一种核酸，不能在活细胞内生长繁殖
C．无典型细胞结构，仅由核心组成，核心中只有一种核酸，只能在活细胞内生长繁殖
D．有典型细胞结构，由蛋白质衣壳组成，不能在活细胞内生长繁殖
E．无典型细胞结构，仅由核心和蛋白质衣壳组成，核心中有两种核酸，只能在活细胞内生长繁殖
参考答案：A
| Modem cowboy seem to be giving up the bandanna (印花大手帕) handkerchief; yet there was a time when this article was almost as necessary to a cowboy’s equipment as a rope, and it served for purposes almost as varied. The bandanna made a good sling for a broken arm; it made a good bandage for a blood wound. Early Irish settlers on the Nueces River used to believe that a bandanna handkerchief that had been worn by a drowned man would, if cast into a stream above the sunken body, float until it came over the body and then sink, thus locating the body. Many a cowboy out on the lonely plains has been buried with a clean bandanna spread over his face to keep the dirt, or the coarse blanket on which the dirt was poured, from touching him. The bandanna has been used to hang men. Rustlers used to "wave" strangers around with it as a warning against nearer approach, though the hat was more commonly used for signaling. Like the Mexican sombrero (阔边帽) or the fourgallon Stetson, the bandanna could not be made too large. When the cowboys of the Old West make their final parade on the grassy shores of Paradise, the guidon (旗手) that leads them should be a bandanna handkerchief. It deserves to be called the "flag of the range country". |
A Stetson is a ______.
A．large bandanna
B．Mexican sombrero
C．tough vaquero
D．wide-brimmed hat