He hasn't come, ______ I telephoned him yesterday.
A:when
B:while
C:although
D:after
做“硫在氧气里燃烧”的实验时,要在集气瓶中预先装少量的水,其目的是____该反应既是化合反应,又是____反应。
Tony goes to a special school for the ____ (able) children.
动物奔跑时消耗的能量主要来自( )