Mexican painter Frida Kahlo drew inspiration from her Mexican heritage, where she incorporated native and religious rymbols into her work/

   a. where she incorporated

   b. in which she incorporated

           c. incorporated

           d. incorporating 

           e. therefore, she incorporated

                           c,d 都是非谓语, 为什么非得选d而不是c呢?

2. Females were not allowed to compete in the Olympic games of ancient Greece; they were not even allowing htem to watch it.

           a. allowing them to watch it

           b. allowed to watch them

           c. allowed watching

           d. allowed watching them

           e. allowing their watching

                     答案是 b, them 不会指代不清吗?