资源广、燃烧值高、无污染的新型能源是[ ]
A.煤
B.石油
C.天然气
D.氢气
答案:D
A talk on Chinese history __________in the school hall next Monday.
A.be given
B.has been given
C.will be given
D.will give
十三号车钩提高牵引吨位最有效,最经济的措施是采用低合金高强度铸钢制造。