阅读短文，选择正确的一项。

      I'm Lucy. I love travelling (旅行). Every summer I go on trips. I often buy postcards and stamps there

and send the postcards to my friends. I usually send some e-mails to my friends, too. I tell them some

interesting stories. I want to invite (邀请) my friends to travel with me.

1. Does Lucy like to travel?

A. Yes, she does.

B. No, she doesn't.

2. What does she buy there?

A. A computer.

B. Some postcards and stamps.

3. She wants to tell her friends some stories. What does she do?

A. She writes a letter.

B. She sends some e-mails.

某燃气锅炉房要设计一个调压站。已知燃气最大流量为2500m³/h，最小流量为2000m³/h，调压站进口气绝对压力P¹=0.25～0.5MPa，调压器出口绝对压力P₂＝0.15MPa，标态时燃气密度ρ₀-0.7435kg/m³，燃气温度为t=20℃。调压器前有快速安全切断阀，燃气的相对分子量为16.654。则该调压站需选用公称直径为（）mm的全启式燃气安全阀。全启式燃气安全阀公称直径的可选值为：25，32，40，50，80，100（mm），流量系数为0.6。

A．25

B．32

C．40

D．50