放疗摆位中楔形板的允许精度为()
A.80%
B.85%
C.90%
D.95%
E.100%
参考答案:E
试管婴儿、试管苗、克隆羊三者均属于生物工程技术的杰出成果,下面对其生物学原理及技术的叙述正确的是[ ]
A.都属于无性生殖,能保持母本性状
B.都是细胞工程的技术范围
C.都充分体现了体细胞的全能性
D.都不会发生基因重组和变异
This is a nice city ______ many interesting places. [ ]
A. with
B. have
C. has
D. there are