根据中文提示，用词组的适当形式填空，每空一词。
Hurry up!We are ________ _________(等候)you at the gate．
He was so tired that he _________ _________(入睡)as soon as he lay down．
Michael is _________ _________(擅长)physics but he is weak in chemistry．
Li Lei seldom goes to school ________ ________(步行)．He usually takes a bus there·
A lot of trees were _________ __________(砍伐)．As a result，there were more sandstorms．