下列关于性别遗传的知识叙述正确的是（ ） ①人的23对染色体有23个DNA分子

写出下列昆虫的名称。

1. They jump high in the grass.

2. They fly high in the sky and look like planes.

3. They are very small but they can carry big things.

4. They like dancing in the flowers and they are very beautiful.

5. They are very special. They can glow at night.

6. They like flowers and they work hard.

1. _________ 2. _________ 3. _________ 4. _________ 5. _________ 6. _________

While large numbers of residents in this area ______ the A/H1N1 flu, very few suffered death.

A．picked up

B．took up

C．brought up

D．caught up

某微粒用_Z^AQⁿ⁺表示，下列关于该微粒的叙述正确的是（　　）

A．所含质子数=A-n

B．所含中子数=A-Z

C．所含电子数=Z+n

D．质量数=Z+A

安全阀不参加水压试验。

按卫生监督的对象分类，卫生监督包括（）

A.预防性卫生监督、经常性卫生监督

B.公共卫生监督、医疗卫生监督

C.依职权卫生监督行为和依申请卫生监督行为

D.食品卫生监督、职业卫生监督