下列各种行为中，属于后天性行为的是（ ） ①蜜蜂采蜜后沿原路返回蜂巢②老鼠走迷宫

第一次世界大战后召开的巴黎和会上签署了《九国公约》，确立了战后帝国主义在欧洲、亚洲和非洲的新秩序。

错误：_______________________

理由：_______________________

借助计算器，用二分法求出ln(2x+6)+2=3^x在区间（1，2）内的近似解（精确到0.1）。

(71) is a one -way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string.
(72) is a protocol that most USENET machines now use it to allow news articles to propagate from one machine to another over a reliable connection.
(73) is an approach preferred by cable TV providers. In this solution the fiber terminates at an optoelectrical converter and the final segment is a shared coaxial cable.
(74) is a device used to connect two separate network that use different communication protocol.
(75) is a digital-to-digital polar encoding method in which the signal level is always either positive or negative.

A．NNI

B．NRZ

C．NAK

D．NVT

在换路瞬间，下列说法中正确的是（）。

A.电感电流不能跃变

B.电感电压必然跃变

C.电容电流必然跃变

D.不确定

画矩形时，按能画正方形。（）

A、Ctrl

B、Alt

C、Shift

D、以上说法都不对