混凝土预制桩、钢管桩、钢板桩及沉管灌注桩的施工时，严禁吊桩、吊锤、（）或行走同时进行。桩机在吊有桩或锤的情况下，操作人员不得离开岗位。
参考答案：回转
A．做减速运动
B．做加速运动
C．处于静止或匀速直线运动状态
D．一定处于静止状态
根据句意用所给单词的适当形式填空。
1. Britain is a developed __________(industry) country.
2.More and more people in China are realising the __________(important) of protecting the environment.
3. China’s __________(tour) has improved a lot these years.
4. The way of life has changed a lot in __________(recently) years.
5. Do the _________(India) speak English as their first language?
