B型双螺旋是DNA的普遍构型，而z型被确定为仅存在于某些低等真核细胞中。 ( )
参考答案：错
I hope I'll go to Beijing _____.[ ]
A. sometime
B. sometimes
C. some time
D. some times
若a+3b=2时，则代数式10-a-3b的值为______．
hope I'll go to Beijing _____.[ ]