có 3 lọ mất nhãn đựng 3 dung dịch trong suốt:NaO loãng,FeO và P2O5.Làm thế nào để nhận biết các dung dịch trên bằng PTHH?

Tính chu kì xoắn của gen?

1.-Lee:"How about giving me a hand?"

-Mary:"...................."

A.Not yet          B.I promise        C.Sure.I'll be glad to help             D.You're welcome

2.-Kate:"......."

-Mary:"Don't worry about it'

A.Thank you for inviting me.       B.Sorry for coming late.           C.Could you do me a favor?                                                         D.Do you need any help?

1.After........search,the missing girl was found alive and well at a friend's house.

A.a three-hour     B.a three hour          C.three-hours       D.a three-hours

2.-".......does it take you to get to school every day?"

-"About fifteen minutes"

A.How many  B.How long      C.How often         D.How far

1.I don't want to hear you complaining any more.

A.I've had enough of your complaining

B.I wish to hear you complaining more and more

C.Why don't you complain more?

D.I'm too busy to listen to your complain

1.Ba:"I think we should use paper economically so that we can save trees in the forests"

Lan:"________________________"

A.Congratulations            B.Yes,I'd love to            C.That's a good idea        D.It's nice of you to say so

2.I hurried.............I wouldn't be late for class.

A.since         B.so that        C.as if              D.unless

3.-Harry:"............"

-Kate:"Yes.I'd like to buy a computer.".

A.Do you look for something?            B.Good morning.Can I help you?

C.Excuse me.Do you want to buy it?         D.Can you help me buy something?

1.Ba:"I think we should use paper economically so that we can save trees in the forests"

Lan:"________________________"

A.Congratulations            B.Yes,I'd love to            C.That's a good idea        D.It's nice of you to say so

2.I hurried.............I wouldn't be late for class.

A.since         B.so that        C.as if              D.unless

3.-Harry:"............"

-Kate:"Yes.I'd like to buy a computer.".

A.No,I don't like         B.No,never mind         C.I'd rather you didn't.It's stuffy.

1.Would you please.......me where the post office is?

A.say       B.explain        C.point     D.tell

2.After Nga's birthday,her mother was the only person........the house.

A.clean         B.cleaned       C.cleaning     D.to clean