——Would you like to come to my house for dinner tonight?——I'd love to , _____ I have lots of work to do .
A：so
B：or
C：and
D：but
太阳活动是 ( )
下列实验方法中错误的是( )
某动物细胞中精子中有4条染色体，那么本物种体细胞中的染色体数目为（ ）
