—Remember to learn this poem _____ heart.

—Yes, I will. [ ]

A. on

B. by

C. with

D. through

高温阀的温度t为（）。

A.t＞450℃

B.120℃＜t≤450℃

C.-30℃≤t≤120℃

D.t＜-30℃