若某管子的外径为57mm，壁厚为3mm，则管子的规格型号可表示为（）。
A.Φ50×3
B.Φ51×3
C.Φ57×3
D.Φ57
参考答案：C
My name is Nancy. I have a brother and a sister, Paul and Laura. For breakfast, Paul likes eggs and bananas. Laura and I like hamburgers and bananas. For lunch Paul likes salad and hamburgers. We like vegetables and oranges. And for dinner Paul has fish and potatoes, we have French fries and bread(面包). We really like French fries.
请根据短文内容，判断正（T）误（F）。
小题1:Paul likes eggs and apples for breakfast.
小题2:There are three girls in the family.
小题3: Paul, Laura and Nancy all like bananas for breakfast.
小题4:. Paul doesn’t like hamburgers.
小题5: Nancy and Laura like vegetables and oranges for lunch.
已知1个质子的质量mp=1.007277u，1个中子的质量mn=1.008665u．氦核的质量为4.001509u．这里u表示原子质量单位，1u=1.660566×10-27kg．由上述数值，计算2个质子和2个中子结合成氦核时释放的能量．（1u的质量亏损对应的结合能为931.5MeV）
