根据1989年国际救助公约，如果救助人因其救助作业防止或减轻了环境损害，船舶所有人应

证券投资基金在我国的作用主要包括（ ）。

A．为中小投资者拓宽投资渠道

B．提高投资者的投资回报

C．优化金融结构，促进经济增长

D．促进证券市场的稳定和健康发展

As she walked round the huge department store, Edith reflected how difficult it was to choose a suitable Christmas present for her father. She wish that he was as easy to please as her mother, who was always delighted with perfume.
Besides, shopping at this time of the year was a most disagreeable experience; people trod on your toes, poked you with their elbows and almost knocked you over in their haste to get to a bargain ahead of you.
Partly to have a rest, Edith paused in front of a counter where some attractive ties were on display. "They are real silk", the assistant assured her, trying to tempt her. "Worth double the price. " But Edith knew from past experience that her choice of ties hardly ever pleased her father.
She moved on reluctantly and then quite by chance, stopped where a small crowd of man had gathered round a counter. She found some good quality pipes on sale—and the prices were very reasonable. Edith did not hesitate for long: although her father only smoked a pipe occasionally, she knew that this was a present which was bund to please him.
When she got home, with her small well chosen present concealed in her handbag, her parents were already at the supper table. Her mother was in an especially cheerful mood, "Your father has at last to decide to stop smoking. " She informed her daughter.

Edith’s father smoked a pipe ______.

A．when he was obliged
B．on social occasions
C．from time to time
D．when he was delighted

用量不可过小，应使病人稍呈青紫的是（）.

A．亚甲蓝

B．硫代硫酸钠

C．亚硝酸钠

D．依地酸钙钠

E．二巯基丙醇

应每（）h记录一次罗茨流量计读数，计算出排量。

A、1

B、2

C、3

D、4

当用TEMS测得的TA值为5，则此时TEMS离BTS的距离是：（）

A、5M

B、2500M

C、1250M

D、500M