( ).--I saw Betty go to Grandpa Li's home just now.  --Yes.She’s often seen _________ the old man with the housework..  A:help B.to help C.helps D.helped答案选择B.这道题的意思我都没弄懂,更不会选择了.它是一个固定搭配吗?还是什么其他的,麻烦讲清楚一点.

问题描述:

( ).--I saw Betty go to Grandpa Li's home just now.
  --Yes.She’s often seen _________ the old man with the housework..
  A:help B.to help C.helps D.helped
答案选择B.这道题的意思我都没弄懂,更不会选择了.
它是一个固定搭配吗?还是什么其他的,麻烦讲清楚一点.