艾滋病的全称是“获得性免疫缺陷综合症”，其病毒感染人体后，会破坏人体某种功能而导致各种病症的出现，此功能为（　　）

小明在水盆中洗碗，发现一个大碗正漂浮在水盆中，如图所示．他将水盆中的一些水放入大碗中，但大碗仍然漂浮．与原先相比，大碗所受到的浮力将____  （选填“变大”、“不变”或“变小”），水盆中的水面将会____  （选填“上升”、“不变”或“下降”）．

口算下列各式．

240×20=	600÷30=	60×200=	420万﹣160万=
1000÷1000=	120×50=	300﹣300÷6=	12亿+68亿=

根据短文理解，完成各题任务。
C
    Sally is an English girl. She is my English teacher, Mrs. Brown's daughter. She is only five years old. (A)She can't go to school. She likes playing ping-pong.
    Her favorite ping-pong player is Zhang Yining. Sally is in the ping-pong club. She goes to the ping-pong club every day. She plays ping-pong for two hours there.
    Sally has a sister. Her name is Maria. She is in our class. She likes running. She runs with her mother every morning. (B)她最喜欢的赛跑明星是刘翔. Maria says she wants to be a running star like Liu Xiang.

圣弗朗西斯科（旧金山）位于38°N，是美国太平洋沿岸的最大的港口，这里的气候类型属于（　）