下列有关癌细胞的叙述正确的是[ ]
A.癌细胞膜上糖蛋白少,细胞中核糖体多
B.癌细胞分裂速度快,无分裂间期
C.癌细胞中DNA含量多于正常的细胞
D.病毒不能诱发细胞癌变
答案:A
I'm waiting for my friend. , I will go shopping alone. [ ]
A. If she comes
B. If she won't come
C. If she doesn't come
设备出现故障,应该按照哪一个程序来做?