问题：
[单选] By the time you arrive, I ________ working for two hours．
By the time you arrive, I ________ working for two hours．
问题：
[单选] Not only the switches but also the old wiring ________ changed．
Not only the switches but also the old wiring ________ changed．
问题：
[单选] ________had he arrived home than it began to rain．
________had he arrived home than it began to rain．
问题：
[单选] 回答题Eggs are my favorite food．I like them 21 ，hard-boiled，scrambled，or poached．I eat eggs for
回答{TSE}题Eggs are my favorite food．I like them 21 ，hard-boiled，scrambled，or poached．I eat eggs for 22 ，lunch，and dinner．I eat eggs here，there，and everywhere!&nb
问题：
[单选] 一般情况下，机体所需能量由糖提供（ ）
一般情况下，机体所需能量由糖提供（ ）
问题：
[单选] 进食后，使机体产生额外热能最多的是（ ）
进食后，使机体产生额外热能最多的是（ ）
问题：
[单选] 对尺神经的描述，错误的是 （ ）
对尺神经的描述，错误的是 （ ）
