搜题请搜索小程序“爱下问搜题”
问题
填空题
止回阀按其结构不同分为（）式止回阀和（）式止回阀。
答案
参考答案：升降；旋启
填空题
看图选择正确的单词或短语填空。
Model: Let's go to the restaurant to have supper.
shop, market, restaurant, movie theatre, library, watch a movie,
read books, buy a dress, eat dumplings, buy fruit
1. Let's go to the _____________ to ______________________.
2. Let's go to the _____________ to ______________________.
3. Let's go to the _____________ to ______________________.
4. Let's go to the _____________ to ______________________.
5. Let's go to the _____________ to ______________________.
查看答案
选择题
以下哪些不是自然光源（ ）
A．水母
B．萤火虫
C．蜡烛
D．太阳
查看答案
