____ in a branch of the tree ___ a note which read "I'll meet you at the School Gate".

A．Sticking; was there

B．Stick; was there

C．To stick; was

D．Stuck; was

石油中氢元素占（）。

A、1％～2％

B、3％～5％

C、5％～10％

D、10％～14％