_____Friday afternoons,many students are sleepy after a long week of classes. A.In B.On C.At
—Could you help me ____ my Chinese?—No problem.
—____ are new here. Let’s help ____.—OK.
—Where does he ____?—He ____ in Shanghai.
Can I________ you some questions ?
---Is this ________ white ruler ?---No. ________ is yellow.