乙醚中含有水，能将试样中糖及无机物抽出，造成测量脂肪含量结果的误差。
参考答案：对
After his wife died in an accident, he had to keep himself________to forget his sorrow for the time being. [ ]
A. occupy
B. occupying
C. occupied
D. to occupy
造成发动机油压力高的原因是（）。
A、机油粘度大
B、机油泵泵油不良
C、机油粘度低
D、限压阀弹簧软
