我是tutorial package的新手。确实很棒，但是我不知道如何设置练习以便预先加载软件包。
我已经尝试过了，但是当我在浏览器中打开html文件时，它基本上不会安装和加载软件包。
---
title: "Example"
author: "Author"
date: '2018-08-27'
output: html_document
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
#The following line is only included if you need to install the tutorial package
#install.packages('tutorial', repos='https://mirror.its.sfu.ca/mirror/CRAN/')
library(tutorial)
```
```{r, include=FALSE, eval=T}
tutorial::go_interactive()
```
```{r ex='loading-data', type='pre-exercise-code'}
install.packages('tidyverse')
install.packages('haven')
library(tidyverse)
library(haven)
```
```{r ex='loading-data', type='sample-code'}
ces<-read_sav(
'https://github.com/sjkiss/2018/raw/master/Materials/R/ces15.sav'
)
head(ces)
```