假设使用一种加密算法，它的加密方法很简单：将每一个字母加5，即a加密成f。这种算法的密钥就是5，那么它属于()。
A、对称加密技术D
暂无解析
Ithasbeenyears________Ireturnedhome.
Jameshasjustarrived,butIdidn’tknowhe________untilyesterday.
Whichofthefollowingispartiallyconverted?
—Davidhasmadegreatprogressrecently.—_______，and_______.
Thereisanambiguityinthesentence“Heisahardbusinessman”dueto______.
