Question

This woman _______ his mother.

1. A.
   maybe
2. B.
   may be
3. C.
   may is
4. D.
   perhaps

Answer 1

B
perhaps意为“也许”，作状语，修饰动词，本句缺少谓语，可排除A、D。may为情态动词，后面应该跟动词原形，所以may is也是错误的，故选B。