问题
选择题
Cloning plants is straightforward cloning animals is very complicated .
A．so that
B．although
C．while
D．as if
答案
答案：C
词义辨析题。A. so that 为的是 B. although 尽管 C. while 然而 D. as if 似乎 句意：克隆植物直接然而克隆动物非常复杂。 根据语境选C