粘合法密封有两种方法,基本特性是()均较差,不能作为单一、可靠的密封方法。
参考答案:密封性能
阅读短文,判断正(T)误( F)。
New Year's Day is coming. Now it's December. My sister and I do some shopping in the supermarket.
There are many things for new year. I want to buy a pair of shoes, a coat and a pencil case. My sister wants to
buy a story book, a scarf, a pen and two cards. She wants to send the cards to her friends.
How happy we are!
( ) 1. Teachers' Day is coming!
( ) 2. My sister and I go shopping.
( ) 3. I want to buy a scarf.
( ) 4. My sister wants to buy two cards.
( ) 5. We are happy.
水平接地体相互距离应不小于()米。
A.2
B.3
C.4
D.5