仔细分析电路原理,判断故障所在。要测试必要点的( ),多做一些试验,以便于分析。
A.电流或波形
B.电压或波形
C.电压或电流
D.电阻或电流
参考答案:B
用所给动词的适当形式填空。
1. He can help me (mend) the bike.
2. One of the children (fly) a kite now.
3. Let Li Lei (clean) the classroom.
4. It's six. It's time (read) English.
5. Look! they (eat) apples?
“空白抬头,空白背书”提单是指______。
A.提单正面"Consignee"一栏空白,由托运人在提单背面签字
B.提单正面"Consignee"一栏空白,无须背书
C.提单正面"Consignee"一栏填"To Order",由托运人在提单背面签字
D.提单正面"Consignee"一栏填写"To Bearer",无须背书