8751单片机内有4KB EPROM，如果从内部EPROM取指令必需将1个引脚作适当连接，即()

A. E(aX+b)＝aE(X)+b
B. F(X1+X2)＝E(X1)+E(X2)
C. var(X1±X2)=var(X1)+var(X2)
D. var(aX+b)＝avar(X)

A. (0，a)
B. (a，b)
C. (0，b)
D. (0，0)

A. The departing ships seemed to be smaller and smaller when they sailed away.
B. The greater a concentration of mass is at the poles, the stronger its gravitational pull.
C. The length from Earth's center to sea level at the equator is longer than that at the poles.
D. The changes in the rising of a few millimeters on Earth's surface detected by modern devices.

A. Customers can offer their friends some good advice about shopping.
B. Some firms will make a large profit from loyal customers.
Customers can find their favorite colors.
D. Customers can get in touch with sellers efficiently.