能判断出利手的年龄约为（）。
A.2～4岁
B.3～5岁
C.4～6岁
D.5～7岁
E.6～8岁
参考答案：C
His teacher kept telling him that he should recite the text, but _______ didn't help. [ ]
A. it
B. she
C. he
D. which
每千克标准煤发热量为（）kJ。
A.20934；
B.25120.8；
C.29307.6；
D.12560.4。
