确定溃疡癌变最可靠的是( )
A．胃镜下活检找到癌细胞B．胃钡透龛影直径为2.5cmC．大便隐血持续阳性D．无节律性上腹痛E．胃酸减少
参考答案：A
用括号中所给单词的正确形式填空。
1. For children, ______ (clean) their bedrooms themselves is a good habit.
2. Thanks for ______ (invite) me to your home for dinner.
3. Maria, could I use your MP4 ______ (play)?
4. Could you please clean the ______ (live) room?
5. The girl is old enough ______ (make) her bed.
分析电机在无负荷时不转的原因。
