目前，临床上对于铸造钛及钛合金制作修复体，常用的方法是（） A.机床切削加工 B.焊

首字母填空。

     Zhalong is a n__1__ reserve in Heilongjiang in northeast China. It's one of the w__2__ most important wetlands. The area is a great p__3__ for wildlife. It's the ideal home for different kinds of plants, fish and

b__4__. Many birds live there. There are a lot of fish in the wetlands, and the birds catch t__5__ for food.

     Each year many people go there to w__6__ the rare red-crowned cranes, b__7__ Zhalong Nature

Reserve has an important living a__8__ for them.Many people don't understand the i__9__of the wetlands

. We should help them understand and make them take a__10__ to protect wildlife.

分解淀粉为麦芽糖的是（）

A.胃蛋白酶

B.淀粉酶

C.胰脂肪酶

D.辅脂酶

E.胰蛋白酶

点P（0，m）在y轴的负半轴上且m>-1，则点Q（-m²-1，-m+1）在直角坐标系中位于第（    ）象限。

甲某因泄愤，在夜晚先后到乙某、丙某、丁某3家打麦场(不在一起)上放火，烧毁乙某的麦子3000公斤、丙某的麦子5000公斤、丁某的麦子3500公斤，造成直接经济损失10000元。甲某的行为()

A．故意毁坏财物罪

B．不构成犯罪

C．构成破坏生产经营罪

D．构成放火罪

为了便于使用单位定期地校核航行资料，应当至少每（）印发一次航行资料校核单。

A.三个月

B.半年

C.二个月

D.28天