—Guess what? I happened to have met Mark at the party last week.
—If my memory serves me correctly, you two ________ each other for almost ten years.
A:haven't seen
B:hadn't seen
C:didn't see
D:don't see
看下图日本经济结构图,关于日本经济的叙述正确的是( )
应用基因工程技术诊断疾病的过程中,必须使用基因探针才能达到检测疾病的目的。这里的基因探针是指 ( )
在下列生态系统中,调节能力最强的是( )
选择正确的汉语意思:animal( )