四川煤炭资源蕴藏量最多的地区是（）。
A、成都平原地区
B、攀西地区
C、川南地区
D、甘孜州
参考答案：C
Though great efforts have been ___ on their study , Annie still can’t make any improvements , which
makes her parents greatly ______ . [ ]
A. made ; disappointed
B. done ; disappointing
C. taken ; disappointed
D. given ;disappointing
已知，在常温常压条件下，氢气的热值为143kJ/g，请写出该条件下H2燃烧的热化学方程式______．
