问题
单项选择题
血磷降低能促进哪种物质增多
A．1，25-(OH)2D3
B．胰高糖素
C．PTH
D．促胃液素
E．降钙素
答案
参考答案：A
搜题请搜索小程序“爱下问搜题”
血磷降低能促进哪种物质增多
A．1，25-(OH)2D3
B．胰高糖素
C．PTH
D．促胃液素
E．降钙素
参考答案：A
| 完形填空。 | ||||
| In the past all letters were sent by train or ship. Now most letters are __1__ sent by train or ship, but some are sent by air. You send a letter __2__ so that your friend may receive it sooner. A letter __3__ about twelve days to go from England to India by train or by ship. A letter can get to India by air __4__ five days now, but __5__ the time may be made shorter. __6__ people were afraid to send letters by air. They thought that the plane might fall and their friends might not receive the letter. So they sent two letters: one letter by air and __7__ by train or ship. They wanted to __8__ that the letters would be received. Planes are now almost as safe __9__ trains or ships. __10__ letters are sent by air, | ||||
|