下图示意不同纬度四地白昼长度变化。完成1—3题。

1、若该圈表示上半年a、b两月（a月早于b月），则①、②、③、④四地纬度依次是[ ]

A．66.5°N、66°N、40°N、40°S

B．66.5°S、66°S、40°S、40°N

C．66.5°N、66°N、0°、40°S

D．66.5°S、66°S、0°、40°N

2、根据图中各地的白昼长度变化可知[ ]

A．a月内①—④各地的夜长均长于昼长

B．b月内①—④各地的昼长均长于夜长

C．③地较②地昼夜长短的年变幅大

D．③地与④地之间的某一纬度上昼夜长短变化为零

3、①地在a月与b月的平均昼长变化Pa与Pb的关系应符合[ ]

A．0<pa/pb<1

B．Pa/Pb=0

C．pa/pb=1

D．Pa/Pb>l

Future Computer Trends:
The components of a PC will be built into the (6) and large plasma or electroluminescent flat panel display hanging on a partition wall will act as both a (7) and videophone display.
A high resolution, touch sensitive LCD (8) into desktop will allow pan-based pointing and data input. In the home, meanwhile, computers will become as ubiquitous as TVs.
Computer interfaces will be far friendlier than (9) graphical user interfaces (GUI) of today. Computers will use "human interfaces" based on multimedia.
RISC microprocessors will finally obliterate the ever thinning gap between workstations and PCs. Similar advances in nonvolatile flash memory will lead to the replacement of magnetic (10) disks with electronic "silicon disks".

A．desk

B．monitor

C．built

D．mouse-driven