—Why didn’t you remind him of the possible danger?

—But what _______ otherwise? He never listens to me.

A. could I do   B. could I have done    C. should I do         D. must I have done

—You didn’t invite Mary to the ball?

    —____ her, too?

    A. Must I invite    B. Should I have invited

    C. Must I have invited     D. Should I invite

--Must I do it now?

--No, you _____.

A. won’t              B. needn’t               C. can’t          D. don’t

---Must I take this medicine, Mom? It ________ so terrible.

---Yes, you must take it for another three days.

A. is tasting      B. is tasted        C. tastes          D. has tasted

—Must I turn off the gas after cooking ? 

--Of course . You can never be ___ careful with that.

    A．enough          B．too            C．so             D．very