目前,我国各民主党派的性质是:
A.无产阶级政党
B.资产阶级政党
C.群众团体
D.为社会主义服务的政治力量
答案:D
I ______ her, but I never could. [ ]
A. ought to help
B. must help
C. must have helped
D. ought to have helped
燃料的燃烧性是指()。