1. [单选题]He did not regret saying what he did but felt that he it differently.
A. could express
B. would express
C. could have expressed
D. must have expressed
2. [单选题]衣藻的减数分裂为合子减数分裂。( )
A. 正确
B. 错误
3. [单选题]某人群中某常染色体显性遗传病的发病率为19%，一对夫妇中妻子患病，丈夫正常，他们所生的子女患该病的概率是
A. 10/19
B. 9/19
C. 1/19
D. 1/2
