“外形高点”是指（）

A.牙冠邻面相接触点

B.牙冠最突出的点

C.牙冠各面最高的点

D.牙冠颊面最突出的部分

E.牙体轴面最突出的部分

根据句意，在答题卡标有题号的横线上，写出括号内所给单词的适当形式。

小题1:His effort made the two companies reach an _____________ in the end. (agree)

小题2:These engineers __________ developed a new kind of energy saving car last year. (success)

小题3:We all felt ___________ to find out he wasn’t involved in this murder. (relax)

小题4:He has lung cancer because of ___________ second hand smoke for many years. (breathe)