You eat too much candy. It's too bad _____ your teeth.
with
to
for
根据本题语境可知，吃太多糖对牙齿没有好处，be bad for… 意为“对……没有好处；对……有害”，故答案为选项D。
Remember _____ the door when you go out.
close
closing
to close
closed
句意：当你出去的时候记得关门。由此可知，“关门”这件事还没有做，此时要用 remember to do sth. 的搭配，故答案为选项C。