单项选择题

The DNA in the sperm cells can be measured ________.

A．in the same way how the cattle are herded
B．when they pass through a tube one behind the other
C．after they pass through a laser tube
D．when they are scanned by a laser detector all at a time

<上一题目录下一题>

热门试题

单项选择题

According to this passage, the practice of sex selection ________.

A．can help to prevent all genetic problems
B．is totally unacceptable to ethics experts
C．was already realized five hundred years ago
D．will benefit families with certain inheritable diseases